As long as we have been on earth, we have used the sea around us. We take from the ocean and we give (41) it. We take fish from the ocean — millions of kilograms of fish, every year, to (42) millions of people. We even use (43) bones for fertilizer and meal. We take (44) from the ocean. One way to get salt (45) sea water in a shallow basin and leave it (46) it evaporates. Along with salt, other minerals are left after evaporation — iodine (碘), magnesium(镁), and bromine(溴), to (47) a few. Much gold and silver drift (48) in the waters of the sea, too. But the sea does not (49) them up by evaporation. Other gifts from the sea are pearls, sponges(海绵), and seaweed. Pearls become jewelry. (50) sponges become cleaning . Seaweed becomes (51) of many kinds — even candy, jellies, and ice cream — (52) medicine. Believe it or (53) , fresh water is another gift from the sea. We (54) drink ocean water. Some of its contents may cause illness. (55) ocean water becomes fresh water when the salts are removed. In the future, we will find (56) depending more and more on fresh water from the sea. The sea gives us food, fertilizer, minerals, water, and other (57) . What do we give the sea Garbage. We pollute the ocean when we use it as a garbage dump. Huge (58) it is, the ocean cannot hold all the waste that we pour into it. Dumping garbage into the ocean is killing (59) sea life. Yet as the world population grows, we may need the sea and its gifts more than ever. We are finally learning that if we destroy our seas, we might also destroy ourselves. (60) , it’s not too late.