Section ⅠUse of English

Sleep is divided into periods of so-called REM sleep, characterized by rapid eye movements and dreaming, and

longer periods of non-REM sleep.

1

kind of sleep is at all well-understood, but REM sleep is

2

to serve

some restorative function of the brain. The purpose of non-REM sleep is even more

3 . The new experiments,

such as these

4

for the first time at a recent meeting of the Society for Sleep Research in Minneapolis, suggest

fascinating explanations 5

of non-REM sleep.

For example, it has long been known that total sleep 6

is 100 percent fatal to rats, yet, 7 _examinations of the

dead bodies, the animals look completely normal. A researcher has now

8

the mystery of why the animals die. The rats 9

bacterial infections of the blood, 10

their immune

systems—the self-protecting mechanisrn against disease—had crashed.

1. [A] Either

[B] Neither

[C] Each

[D] Any

2. [A] intended

[B] required

[C] assumed

[D] inferred

3. [A] subtle

[B] obvious

[C] mysterious

[D] doubtful

4. [A] maintained

[B] described

[C] settled

[D] afforded

5. [A] in the light

[B] by virtue

[C] with the exception [D] for the purpose

6. [A] reduction

[B] destruction

[C] deprivation

[D] restriction

7. [A] upon

[B] by

[C] through

[D] with

8. [A] paid attention to [B] caught sight of [C] laid emphasis on

[D] cast light on

9. [A] develop

[B] produce

[C] stimulate

[D] induce

10. [A] if

[B] as if

[C] only if

[D] if only