A. Natural sponges become cleaning aids.
B We pollute（污染） the ocean when we use it as a garbage dump（垃圾堆）。
C The area of the sea is becoming smaller and smaller.
D Along with（连同。。。一起） salt， other minerals are left（留下） after evaporation.
F Some of its contents may cause illness.
We take minerals（矿物质） from the ocean. One way to get salt is to place seawater（海水） in a shallow（浅的） basin（水池） and leave（留下） it until it evaporates（蒸发）。 __2__。 Much gold (黄金) and silver（白银） drift（漂浮物） dissolved in （溶解入）the waters of the sea， too. But the sea does not give them up by simple evaporation.
2．D． 选项D中有三处词语分别与空格前句中的词语呼应（salt – salt， minerals – minerals， evaporation – evaporate）， 而D中的mineral与空格后句中的gold， silver构成主题相关词，因此D是答案。
A Natural sponges（海绵） become cleaning（清洁） aids（帮助， 有帮助作用的东西）。
B We pollute（污染） the ocean when we use it as a garbage dump（垃圾堆）。
C The area of the sea is becoming smaller and smaller.
F Some of its contents may cause illness.
Other gifts（礼物） from the sea are pearls， sponges and seaweed. Pearls （珍珠）become jewelry（珠宝）。 __3__。 Seaweed（海草） becomes food of many kinds – even candy， and ice cream – as well as medicine. Believe it or not， fresh water is anther gift from the sea. We cannot drink ocean water. __4__。 But ocean water becomes fresh water when the salts are removed. In the future， we will find ourselves depending more and more on fresh water from the sea.
3．
A 选项A的句子结构与前后句中的句子结构形成排比结构， 而且也在讲述海里的物品（海绵）的用途， 因此A是答案。
B We pollute（污染） the ocean when we use it as a garbage dump（垃圾堆）。
C The area of the sea is becoming smaller and smaller.
F Some of its contents（内容， 所含之物） may cause（造成） illness（疾病）。
Believe it or not， fresh water is anther gift from the sea. We cannot drink ocean water. __4__。 But ocean water becomes fresh water （淡水）when the salts are removed（去除，拿走）。 In the future， we will find ourselves depending more and more on fresh water from the sea.
4．F．虽然B中有两个词语分别于空格4前句中的词语呼应（we – we， ocean – ocean ）， 但是B出现在空格中时与空格前后句之间的衔接不自然， 因此B不是答案。 F与空格前句之间是“观点与解释”的关系。
B We pollute（污染） the ocean when we use it as a garbage dump（垃圾堆）。
C The area of the sea is becoming smaller and smaller（越来越小）。
The sea gives us food， fertilizer（化肥）， minerals， water， and other gifts. What do we give the sea？ Garbage. __5__。 Huge（巨大的） as it is， the ocean cannot hold（容纳， 保持， 拥有） all the water we pour into (倒入， 涌入) it， we may need the sea and its gifts（礼物） more than ever（曾经）。
5．B 选项B中有两处词语分别与空格前句中的词语呼应（we – we， garbage – garbage dump）， 因此B很可能是答案。