If you have swum in the1,you know that the water is salty.Ri

If you have swum in the1,you know that the water is salty.Rivers2salt from the land into the sea.Some parts of the sea are3salty than other parts.Do you___4 __the Dead Sea inArabia?It is very5.Swimmers can't6init.It is a7sea.
In8parts of the sea,there are a lot of fishes and plants.Some live near the top of the sea.9live deep down.No light can reach the depths of the sea,10it is completely dark.Strange fish live there.Some are11.Some have their own light.Some have great jaws.12their great jaws,they can swallow(吞下) fish13than themselves.
The sea can be very14.Deep-sea divers know this15,16the top of the water may be warm.Then17the divers go down,the sea becomes18.Manyscientists are now making a study of19and plant20inthe sea.They hope to find new resources(资源) for mankind.
1.A.seaB.riverC.lakeD.canal
2.A.carryB.bringC.leadD.send
3.A.asB.muchC.veryD.more
4.A.recognizeB.understandC.knowD.realize
5.A.heavyB.blueC.saltyD.clear
6.A.dieB.sinkC.drinkD.swim
7.A.strangeB.beautifulC.wonderfulD.deep
8.A.anyB.mostC.fewD.a few
9.A.OtherB.The otherC.The othersD.Others
10.A.andB.butC.soD.though
11.A.aliveB.blindC.commonD.dead
12.A.UseB.InC.WithD.Without13.A.largerB.weakerC.smallerD.cleverer
14.A.coolB.wideC.deepD.cold
15.A.goodB.wellC.quite goodD.quite a few
16.A.atB.onC.overD.above
17.A.asB.whenC.sinceD.while
18.A.darker and darkerB.warmer and warmer
C.colder and colderD.deeper and deeper
19.A.an