One way you can tell if an animal is sleeping is by studying its brainwaves.When human beings or other mammals（哺乳動物） fall asleep，the pattern of their brainwaves changes.
   Mammals' brains are different from fish's brains.Humans and other mammals have complex（復(fù)雜的） brains.A fish's brain is much less complex than a mammal's brain.A fish's brainwaves don't change when the fish is asleep.This means that we can't tell if a fish is sleeping by looking at its brainwaves.
   Although fish may not sleep like people，they do rest.One way to tell if a fish is resting is to watch what it is doing.Most fish will slow down when they are resting.If you have ever had a pet fish，you might have noticed that it will rest near the bottom of the tank for a few hours every night.When the fish rests，it makes very small movements to keep itself in one place.
   Another way to tell that a fish is resting is to watch how it reacts to things that happen to it.When a fish is resting，it will react much more slowly.Several years ago，a group of scientists studied the sleeping habits of zebra fish.They gave the zebra fish mild（溫和的） electric shocks when they were fully awake and while they were resting.If you have a pet fish at home，you can try a similar experiment.Try giving your fish some food when it is resting.It should take much longer for the fish to notice that there is food in its tank than it does when the fish is fully awake.

（1）What happens to their brainwaves when fish are resting？

A

A

A．Their brainwaves stay the same.
B．Their brainwaves become less complex.
C．Their brainwaves die down.
D．Their brainwaves change differently.
（2）What can we learn from the passage？

B

B

A．Fish eat more food when they are resting.
B．Fish react more slowly when they are resting.
C．Fish prefer to stay at the bottom of the tank all day.
D．Fish stop moving when they are resting.
（3）What's the best title for the passage？

C

C

A．Do fish sleep at night？
B．Fun facts of fish.
C．How to know if a fish is resting？
D．Eating habits of fish.
（4）Which part of the magazine does the passage probably belong to？

C

C

A．Travel.
B．Culture.
C．Science.
D．Education.