阅读试题

Passage 26
It’s a good idea to apply sunscreen before heading to the beach if you don’t want to bum. But for marine animals like whales，they don’t have that _1_. Species like sperm whales can spend up to six hours at the ocean’s surface in between dives, _2_ in the sunlight. So how do they protect themselves from a serious case of sunburn?
It turns out that their bodies have a similar defense _3_ against the sun’s UV radiation as people. Blue whales—which have the lightest skin color of the three species—tan during their summer stay before _4_ back to their northern feeding grounds. Sperm whales don’t tan. They can receive an “overdose” of UV radiation during their hours at the ocean’s surface, and they have proteins that _5_ protect their cells from UV damage. This process is _6_ to how human bodies produce antioxidants in response to molecules that can cause a lot of genetic and cellular damage. And fin whales escape sun damage thanks to their high levels of melanin—a dark substance in the skin to protect humans from UV radiation.
Older whales and whales with less _7_ of melanin in their skin—like blue whales—had the greatest level of damage in their mtDNA. Fin whales, which had the greatest amount of melanin, had the least amount of mtDNA damage.
Now that the ozone layer that shields Earth from UV radiation is gradually _8_, it’s important to know what the consequences are for whales and dolphins, especially for _9_ or endangered species. Although it’s difficult to tell what causes many of these skin conditions, UV damage is one cause. Even though whales have _10_ defenses to UV radiation, high exposure can still be harmful.
A) similar B) diminishing C) liability D) migrating
E) mutual F) mechanism G) effectively H) jerking
I) instantaneously J) vulnerable K) content L) baking
M) inherent N) perspective O) option

解题思路

Passage 26
解题思路
1.[O]空格在指示代词that之后，应为名词。that所指与上一句内容有关，指“去沙滩之前先涂上防晒霜”。此处应选择option,表示海洋动物“没有那样的选择”。mechanism通常用于指事物本身内在的机制，不适宜用于指代“涂防晒霜”，故排除。
2.[L]空格所在句子主谓宾结构完整，且空格位于逗号后面，故应为分词作状语，说明鲸鱼在海面逗留六小时的状况。结合上文提到的关于“防晒”的内容，可以推断此处应该说鲸鱼每天“暴晒”六小时，故选baking最合适。
3.[F]虽然空格前的defense是名词，但从句宾语部分意思仍未完整，因此空格应该还是名词，被defense修饰作句子宾语。此处应选mechanism，表明鲸鱼自身拥有防晒的“保护机制”。
4.[D]空格前的before是介词，而空格后紧跟表方位的back to...，可见此处应该选用动词的现在分词，表明鲸鱼在度过了夏天之后的“动向”。动词库中的migrating—词最为恰当，填入文中表示“迁徙到北方去觅食”。
5.[G]空格在主语和谓语之间，故应为副词。本句提到抹香鲸体内的蛋白质可以保护它们不受紫外线的侵害。effectively符合句意，表明这种蛋白质的保护作用很“有效'
6.[A]根据空格后面的内容“人体如何产生抗氧化剂以应对造成大量遗传细胞损伤的分子”可知，本句类比了抹香鲸和人类自身的防护机制，故填人空格的词应含“类似”的意思，similar符合句意。
7.[K]空格在less和介词of之间，应为名词。本段主要讲皮肤黑色素(melanin)含量的多少决定mtDNA受损的程度。填入空格的词应与amount近义，content“含量”符合句意。
8.[B]空格在be动词和副词gradually之后，推断此处应为分词或形容词，说明现在臭氧层(ozone layer)所处的状态。通常指负面影响的consequences提示填入空格的词应为贬义词，因此选用diminishing， 表明臭氧层正在逐渐变小，保护地球免受紫外线辐射的作用也在减小。
9.[J] or提示填入空格的词可能是形容词或分词，与endangered并列；也可能是名词，与species并列。词库中的名词放入句中，句意不通。形容词vulnerable符合句意，表示逐渐减小的臭氧层对“脆弱的”物种会产生特别严重的影响。
10.[M]空格在名词之前，应为名词、形容词或分词作定语。由上文可知，鲸鱼体内有类似防晒霜的保护机制，因此 鲸鱼抗紫外线辐射的能力是自身就有的，故此处用inherent最合适。