The Exploding Lakes of Cameroon
What comes to mind when you think of a lake? You probably imagine a pretty scene with blue water, birds, and fish. For the people in the northwestern Cameroon, however, the image is very different. For them, lakes may mean terrible disasters. In 1984, poisonous gases exploded out of Lake Monoun and came down into the nearby villages, killing thirty-seven people. Two years later, Lake Nyos erupted a cloud of gases rolled down the hills and into the valleys and killed 1,700 people.
Lake Nyos and Lake Monoun are crater (火山口) lakes. They were formed when water collected in the craters of old volcanoes. The volcanoes under Lake Nyos and Lake Monoun are not active anymore. However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake. This is normal in a crater lake. In most crater lakes, these gases are released often because the water “turns over” regularly. That is, the water from the bottom of the lake rises and mixes with the water at the top, allowing the gases to escape slowly.
However, in Lakes Nyos and Monoun, there is no regular turning over. No one knows the reason for this fact, but as a result, these lakes have more gases tapped at the bottom than other crater lakes. In fact, scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases. When a strong wind, cool weather, a storm, or a landslide (滑坡) causes the water to turn over suddenly, the gases escape in a violent explosion.
In the past, no one knew when the gases might explode, so there was no way for the villagers to escape disaster. Now scientists from the United States, France, and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos. They stood a 672-foot plastic pipe in the middle of the lake, with one end of the pipe near the bottom and the other end in the air. Near the top of the pipe, the team put several holes that could be opened or closed by a computer. Now, when the gas pressure gets too high, the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain. With less pressure, a disastrous explosion is much less likely. However, the scientists are not sure that one pipe will be enough to prevent explosions. They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.
To protect people nearby until all of the pipes are in place, the scientists have installed early warning systems at both lakes. If the gas pressure rises to a dangerous level, computers will set off loud sirens (警报) and bright lights to warn the people in the villages. That way, they will have time to escape from the dangerous gases.
1.What will happen when Lake Nyos and Lake Monoun explode?A.Water will flow down the hills. | B.Poisonous gases will be released suddenly. |
C.A strong wind will rise from the lakes. | D.The volcanoes will come to life. |
A.They were formed in 1984. | B.They are at the top of two active volcanoes. |
C.They are not like most other crater lakes. | D.Water in them turns over regularly. |
A.the gases rise to the top and mix with air |
B.people from the villages turn over the water |
C.scientists have put in a computer system |
D.they have more gases trapped at the bottom than other crater lakes |
A.erected a pressure-releasing pipe in the lake | B.identified the gases at the bottom of the lake |
C.built a beautiful fountain near the lakes | D.removed all dangerous gases from the lakes |
A.Scientists are planning to install pipes in all crater lakes | B.Scientists still do not know how to prevent gas explosions |
C.Explosion disasters could be avoided in the future | D.Warming systems have been set up in the villages nearby. |
My Daddy is my hero. He goes to work every day in
Daddy and I do
One morning, I came downstairs and saw Mommy and Daddy
"You know that Daddy
"That's right," Daddy said, "I work every day to help keep people safe.
The day Daddy had to leave, he gave me a big hug. I didn't want him
"I know
Two weeks
A.an | B.a | C.the | D.this |
A.much | B.a lot | C.lots of | D.a little |
A.talk | B.talks | C.talked | D.talking |
A.its | B.it | C.it's | D.itself |
A.had | B.have | C.having | D.has |
A.Sometime | B.Some time | C.Sometimes | D.Some times |
A.whom | B.who | C.which | D.when |
A.pauses | B.pausing | C.paused | D.pause |
A.Before | B.After | C.Until | D.Till |
A.going | B.go | C.to go | D.goes |
A.when | B.what | C.if | D.how |
A.can | B.must | C.may | D.need |
A.with | B.by | C.at | D.in |
A.late | B.lately | C.more lately | D.later |
A.are written | B.is written | C.was written | D.were written |
Last week, students at Northridge High school held a Chinese week. During the Chinese week, many people
There were talks
In the morning, there were lessons about
“The Chinese week was a big
A.enjoy | B.enjoys | C.enjoyed | D.have enjoyed |
A.difference | B.different | C.differently | D.more different |
A.learn | B.learning | C.learned | D.to learn |
A.on | B.in | C.with | D.by |
A.they | B.them | C.their | D.theirs |
A.work | B.worked | C.have worked | D.had worked |
A.a | B.an | C.the | D./ |
A.is | B.was | C.are | D.were |
A.also | B.either | C.as well | D.too |
A.excite | B.exciting | C.excited | D.excitement |
A.write | B.to write | C.writing | D.written |
A.good | B.well | C.better | D.best |
A.for example | B.such as | C.that is | D.in fact |
A.success | B.successful | C.succeed | D.successfully |
A.other | B.another | C.the other | D.others |
Encyclopedia Britannica(《大英百科全书》)used to be the king of encyclopedias. It hopes to become the most important encyclopedia again. An encyclopedia has information about many different things. It includes articles on topics like animals, science, but many people were willing to buy them. They thought Britannica was the best encyclopedia.
A few years ago, the company stopped publishing the books. It put the whole encyclopedia on the Internet. However, Britannica online is not as popular as some other online encyclopedias. About half of Britannica’s articles are free while almost all of the articles on other online encyclopedias are free.
However, Britannica began in Scotland nearly 250 years ago. It moved to Chicago in 1935. In 1990, the company sold more than 100,000 sets of books. It was Britannica’s best year. Book sales dropped after the Internet became popular. People stopped getting information only from books. They began getting it online as well. Some online encyclopedias started in the early 21st century. It was the beginning of the end of Encyclopedia Britannica books. Some online encyclopedias have millions of articles. Britannica has only 106,000. However, Britannica’s articles are more trustworthy(值得信任的). The experts make sure the articles are correct. Britannica covers most of the same general subjects as other’ online encyclopedias, but finding its articles can be more difficult. The Britannica page also has many ads. The ads help support the company.
1.Why is online Britannica less popular than other online encyclopedias?A.More people like to read other online encyclopedias. | B.There are less articles in other online encyclopedias. |
C.The readers can read more free articles in other online encyclopedias. | D.Other online encyclopedias cover most of the same general subjects as Britannica. |
A.In 1935. | B.In 1990. | C.In 1991. | D.In 2002. |
A.They are written by experts. |
B.There is more useful information in it. |
C.The experts check each Britannica article. |
D.Finding Britannica’s articles can be more difficult. |
A.To make money for the company. | B.To make it more user-friendly. |
C.To make its website popular. | D.To help other companies earn money. |
Close your eyes and picture a scientist. Does an image of a man show up in your mind?
It is hard to ignore that even in the 21st century, the “scientist equals male” stereotype (成见)is still there. In the science world, women’s voices are often unheard.
According to UNESCO, only 35 percent of global STEM(science, technology, engineering, and mathematics)students in higher education are women. In taking up science and technology careers, women are more likely to be treated unfairly because of their motherhood and skin color, noted Teen Vogue.
In November, at the 4th World Laureates Forum(世界顶尖科学家论坛)held in Shanghai, some of the world’s top female scientists announced an initiative(倡议), encouraging universities around the world to promote gender equality in STEM areas.
“Role models of women scientists need to be better represented on important international stages and allow their voices to be heard as a way to encourage youths,” Lenore Blum, a female scientist from the US, said at the forum.
In December, Talk With Lu Jian, a Chinese TV show, launched a series of programs under the title of She Power in Tech. The show interviewed Chinese female scientists, including geneticist (遗传学家)Fu Qiaomei at the Chinese Academy of Sciences, Lṻ Zhi, a professor of life sciences at Peking University, and Rong Yi, a chief designer of the Long March 2F rocket.
“These female scientists share a strong passion for science,”said Lu Jian, the TV show’s host. “They are making a pathway for the next women scientists.”
Actions should also be taken to create a better environment for women working in the field of science and technology, noted Science and Technology Daily. For example, they should be given more resources, join in decision-making and gain support for their research during maternity(生育).
1.According to UNESCO’s statistics (统计数字),we can learn that ________ .A.most women do not work during their motherhood |
B.skin color may cause women scientists to be treated unfairly |
C.only 35% of global STEM students are women |
D.women are more interested in the arts than STEM courses |
A.science companies should employ more women scientists |
B.women scientists should have more respect from the world |
C.role models of women scientists should have more chances to encourage young people |
D.the 4th World Laureates Forum gives a good example of gender equality |
A.to celebrate women’s achievement in scientific technology |
B.to show the importance of getting well-educated |
C.to call for gender equality in China |
D.to attract social concern about the stereotype in the science world |
A.she is lucky enough to work together with many top scientists jg |
B.women can also become successful in high-tech fields |
C.rocket designing is a challenging work for women scientists |
D.she is the most remarkable woman scientist in the interview |
A.a lack of resources in high-level education |
B.women’s weakness in competing with men in science |
C.women’s traditional role in society |
D.the amazing achievements of male scientists |
A.beside | B.besides | C.except | D.except for |
A.Too many updates of the apps. | B.Too many functions of the apps. |
C.Too much information they receive. | D.Too much time they spend on the phone. |
A.It stops the users from using willpower. |
B.It checks how much time the users spend on apps. |
C.It lists how many times the users have unlocked the phone. |
D.It shows how many times the users have checked social media apps. |
A.目的 | B.标准 | C.许可 | D.限制 |
A.![]() | B.![]() | C.![]() | D.![]() |
A.Its design is perfect. | B.It may be helpful to some people. |
C.It needs more functions. | D.It has too many functions. |
Many of us learn how to ride a bicycle at a young age. As we grow older, we may stop riding—most of us go to school by bus or by subway. But whenever we get on a bicycle, it’s like we’ve never stopped biking. This is strange. In many other cases, our memories let us down. We often find it hard to remember the name of a person or a place, don’t we? So why can we still ride a bicycle after we stopped riding a long time ago?
It turns out that there are many types of memories. They are stored in different regions of our brains. Memories of experiences (e.g., our first day at school) and of factual (事实的) knowledge (e.g, the capital of France) are declarative memories. These memories can be communicated to others. Skills such as playing an instrument or riding a bike are procedural memories. These memories are responsible for our performance.
Scientists have done many experiments on different memory types. Perhaps the most famous of them was carried out on Henry Gustav Molaison, an epileptic(癫痫患者). In an operation in the 1950s, part of his brain was taken away. After that, the man suffered less from epilepsy. But there was a new problem! Molaison’s memory system went wrong. Through various tests, scientists found he could learn new skills (slowly, though). However, he could never remember having been trained to learn a new skill. In other words, Molaison could develop new procedural, but not declarative, memories.
Scientists have concluded that even with serious brain injuries, procedural memories last much longer. However, they haven’t yet found out why. Some say procedural memories are more lasting because they are stored in the brain’s center.
Now, “It is just like riding a bicycle” has been used as an idiom(习语) in our daily life.
1.In the first paragraph, the writer leads into the topic by ________.A.listing numbers | B.giving examples |
C.describing scenes | D.explaining reasons |
A.The climate of Asia. | B.A birthday party with friends. |
C.A trip to the USA. | D.Swimming. |
A.He couldn’t remember anything. | B.He couldn’t learn a new skill. |
C.He couldn’t remember factual knowledge. | D.He suffered more from epilepsy. |
A.Once learned, it is never forgotten | B.It’s never too late to learn |
C.You should learn with all your heart | D.People can learn from their mistakes |
Jake and Max are twin brothers who have passion for volunteering. Their family has always done community services, and at a young age, they asked guests to donate money towards a charity. Jake and Max have chosen Cookies for Kids Cancer and the American Heart Association, as well as donations (捐赠) to several local places. They came up with some really creative ways to help their community, such as donating a guide dog to the blind.
When they were seven, Jake and Max were interested in volunteering with a family friend at the local homeless shelter to help to cook. Unfortunately, he turned them down because they were too young and had to be fourteen to cook. This led them on an endless task to come up with a way to help other kids who were also facing a similar challenge: wanting to help but being turned down because of their age.
So, Kids That Do Good was created to “show ways to kids or adults, at any age, they could take part in the community and make a difference.”
The small project that started with the twin brothers has grown into a large website that brings thousands of interested visitors each year. Jake and Max say that their website brings 35,000 unique viewers, and of those viewers, Kids That Do Good has connected kids to 16,000 organizations.
Kids That Do Good even has two student board of directors, Steven and Jordan, who are also active in community service, as well as a group of adult advisers.
Jake and Max are busy with school and after-class activities and other community service promises. Kids That Do Good has blog posts that advise kids on building their own charitable event.
1.According to the passage, Kids That Do Good is ________.A.a school | B.a website | C.a homeless shelter | D.a hospital |
A.To help people create charity organizations. | B.To help kids go back to school. |
C.To help people take part in voluntary work. | D.To help the homeless kids and adults. |
A.Being refused to help to cook. | B.A visit to the local homeless shelter. |
C.Doing volunteering work. | D.Helping to cook. |
A.The twins began to do volunteering work at school age. |
B.At a young age, the twins wanted the guests to donate money to Kids That Do Good. |
C.Kids That Do Good has helped lots of kids find ways to do volunteering work. |
D.All those that work for Kids That Do Good are teenagers. |