Sharks Perform a Service for Earths Waters
It is hard to get people to think of sharks as anything but a deadly enemy1: They are thought to____1____people frequently. But these fish2 perform a____2____service for earths waters and for human beings. Yet business and sport fishing3 are threatening their____3____. Some sharks are at risk of disappearing from____4____.
Warm weather may influence both fish and shark activity. Many fish swim near coastal areas____5____their warm waters. Experts say sharks may follow the fish into the same areas,____6____people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person____7____a sea animal, such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the____8____when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack.
A shark has an extremely good sense of smell4. It can find small amounts of substances in water, such as blood, body liquids and____9____produced by animals. These powerful ____10____help sharks find their food. Sharks eat fish, any____11____sharks, and plants that live in the ocean.
Medical researchers want to learn more about the sharks body defense and immune____12____against disease. Researchers know that sharks____13____quickly from injuries. They study the shark in hopes of finding a way to fight human disease.
Sharks are important for the worlds____14____, They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too____15____. This protects the plants and other forms of life that exist in the oceans.
注释：
1.It is hard to get people to think of sharks as anything but a deadly enemy：要让人们相信鲨鱼不是死敌不是一件容易的事。anything but意为决不，远非，如：His performance in London is anything but a success.
2.these fish：这些鱼。Fish单复数同形，如：one fish, two fish, many fish。
3.sport fishing：捕鱼运动
4.sense of smell：嗅觉
练习：
1.A attack B meet C love D visit
2.A terrible B eatable C valuable D possible
3.A source B existence C friends D fish
4.A Space B Sky C Land D Earth
5.A because B since C because of D by reason that
6.A whose B which C that D where
7.A to B for C like D with
8.A times B places C seas D oceans
9.A sciences B mathematics C chemicals D physics
10.A feelings B senses C touches D tastes
11.A those B these C another D other
12.A systems B processes C ideas D circles
13.A recover B reform C return D rely
14.A rivers B oceans C forests D mountains
15.A weak B little C few D great