单选题 Directions: There are 10 blanks in the following passage.
For each numbered blank, there are four choices marked A, B, C and D. Choose the
best one and mark your answer on the ANSWER SHEET with a single line through the
center.
Our planet is like a bit spaceship. Our atmosphere
acts {{U}}(51) {{/U}} a shield against harmful radiation and space
debris. {{U}}(52) {{/U}} holds the air and people on the spaceship,
{{U}}(53) {{/U}} everything doesn't float away. Each of us is an
astronaut and our spaceship, the earth, provides our food and water. The sun is
our energy {{U}}(54) {{/U}} and without it we would not be able to
survive. {{U}} (55) {{/U}} every spaceship, the earth is
a closed system. The only thing we receive from the outside is energy from the
sun. Everything else must be used {{U}}(56) {{/U}} again. We astronauts
don't seem to realize that this spaceship is the {{U}}(57) {{/U}} one
we've got. We {{U}}(58) {{/U}} its resources and waste the energy the
plants have stored from the sun. If we {{U}}(59) {{/U}} our spaceship,
we will destroy ourselves as well. Maybe if we look at the universe which
surrounds us, we will appreciate our own spaceship more and take {{U}}(60)
{{/U}} care of it.
【正确答案】
C
【答案解析】[解析] 本文把我们的行星(即地球)比做飞船，本句说大气层作为屏障，起着阻挡有害辐射和宇宙碎片的作用。act as意为“充当，担任，起……的作用”，正合题意。act like意为“像……一样”；act for意为“代理”。with加某些抽象名词可做状语修饰act(如：act with caution谨慎地行事)，此三选项在此均不恰当。
【答案解析】[解析] 人们使用的太阳能来自太阳，太阳是能量的来源，故应选用energy source这一搭配。resource意为“资源”；origin意为“起源”；supply意为“供应”，如可以说The sun affords us a seemingly endless supply of energy.所以A选项是正确答案。
【答案解析】[解析] 除了来自太阳的能源以外，地球上的一切都要经过多次的循环使用，不是再一次(once)或在某个时候使用(sometime)，更不是永不再用(never)，所以只有over and over意为“反复，再三”是正确选择。
【正确答案】
A
【答案解析】[解析] 地球这艘宇宙飞船是目前唯一能够运载人类的行星，故只有only是正确答案。
【正确答案】
A
【答案解析】[解析] 上句讲人类似乎没有意识到保护地球的重要性，本题只有选abuse its resources“滥用地球资源”才能顺理成章，并与下半句waste the energy意为“浪费资源”合理搭配；utilize意为“利用”；adjust意为“调整”；accumulate意为“积累”均不符合题意。