業精於勤，事立於豫

      Why do we dream? Nobody knows, but everybody __21__. We dream during REM (rapid eye movement) sleep. In eight hours of sleep, people usually have four REM periods. But we __22__ very little. We usually remember only 20 or 30 seconds of REM sleep. There are many ideas about dreams. Some psychologists believe we dream because we need a safe way to do things we can't do where we're __23__ . Some think we dream in order to work out our problems. __24__ believe dreams don't have any special meaning. They are simply thoughts that come to us when we __25__. Whatever you believe, dreams prove one thing—some people have wonderful imaginations.

文意解析：

Why do we dream? (為什麼我們會作夢？)

Nobody knows, but everybody __21__. (無人知曉，但是每個人都會做夢。)

21. (A)understands 了解 (B)dreams 作夢 (C)sleeps 睡覺 (D)does 做

We dream during REM (rapid eye movement) sleep. (我們在睡眠中的快速眼動時作夢。)【REM 快速動眼期】

In eight hours of sleep, people usually have four REM periods. ((在八個小時的睡眠期間，人通常有四小時的快速眼動期。)

But we __22__ very little. (但是我們很少記得。)

22. (A)dream 作夢 (B)sleep 睡覺 (C)remember 記得 (D)move 移動

We usually remember only 20 or 30 seconds of REM sleep. (我們通常只記得快速動眼期睡眠的二十到三十秒。)

There are many ideas about dreams. (關於作夢有很多說法。)

Some psychologists believe we dream because we need a safe way to do things we can't do where we're __23__ . (一些心理學者認為我們會作夢是因為我們需要一個安全的方法去做我們清醒時不能做的事。)

23. (A)awake 清醒 (B)safe 安全 (C)sick 生病 (D)together 一起 

Some think we dream in order to work out our problems. (有些人則認為我們作夢是因為想要解決問題。)

__24__ believe dreams don't have any special meaning. (另一些人則相信作夢沒有其他的意義可。)

* work out (phr.) 解決。

24. (A)Others (B)That (C)We (D)Few 

[考文法] 前句是 some，後句一定是 the others 或 others。這裡是不限定，所以選 others。

They are simply thoughts that come to us when we __25__. (他們單純認為當我們睡覺就會出現夢境。)

Whatever you believe, dreams prove one thing — some people have wonderful imaginations. (不管你相不信與否，作夢的確可以證明一件事 —有些人的想像力眞的很豐富。)

25. (A)dream 作夢 (B)sleep 睡覺 (C)work 工作 (D)remember 記得