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Nowadays transportation is getting more and more important in our daily life. In the past, people had to spend a long time in making a long journey. They also had to move heavy things by hard work. Today, it is very easy for us to go anywhere we choose. We can go by ship, by plane or by car. If we have a lot of heavy things, we can take them to any place where we would like to go in trucks (卡车).
But modern transportation has also brought some problems. Every day we can see a lot of traffic accidents on the road. Our air has become dirtier because of the air pollution. So much noise has made us feel so worried. So I hope to have some transportation with no traffic accidents, no air pollution and no noise in the future.
| The Development of Transportation In the past ★It took people a long time to ★It was hard for people to move heavy things. Nowadays Advantages about today’s transportation ★Going to the places we choose becomes ★Truks can help people carry Disadvantages about today’s transportation ★Transportation causes a lot of ★Transportation causes air pollution. ★Transportation also makes |
同类型试题
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
