The Caffeine Catch
Caffeine, a chemical typically found in coffee, has caused a lot of concern because it is one of the few drugs that show up regularly in our food supply. You probably 1.(use) caffeine since childhood. Caffeine 2.(be) in your first Coke. If you ever enjoyed a chocolate bar, you ate caffeine. Soft drinks are the major source(来源) of caffeine for most children and even some adults. 3.(recent), caffeine has found its way into orange, apple, and other flavored drinks.
Small amounts of caffeine-a cup 4. two of coffee a day—seem safe for most people. However, some people have trouble with even small amounts. One cup of coffee 5. the late afternoon or evening will cause 6.(they) to stay awake almost all night. Larger amounts of caffeine can cause a problem 7.(call) caffeinism. You get very nervous and you can’t sleep.
It is possible 8. caffeine may cause birth defects(缺陷) in humans, too. One study showed that 9.(woman) who drank a lot of coffee, like eight or more cups per day, while they were pregnant were more likely 10.(have) children with birth defects.

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

