关于FISH的叙述正确的是

A:FISH是原位杂交技术的一种 B:具有荧光信号的高灵敏性和直观性特点 C:特异性好,定位准确 D:灵敏性高，与放射性探针相当 E:经济,安全,探针稳定；实验周期短

关于FISH的叙述正确的是（　）

A:FISH是原位杂交技术的一种 B:具有荧光信号的高灵敏性和直观性特点 C:特异性好、定位准确 D:灵敏性高，与放射性探针相当 E:经济、安全、探针稳定；实验周期短

Everyone knows that fish is good for health.  16  But it seems that many people don’t cook fish at home. Americans eat only about fifteen pounds of fish per person per year, but we eat twice as much fish in restaurants as at home. Buying, storing, and cooking fish isn’t difficult.  17  This text is about how to buy and cook fish in an easy way.
18   Fresh fish should smell sweet: you should feel that you’re standing at the ocean’s edge. Any fishy or strong smell means the fish isn’t fresh.   19  When you have bought a fish and arrive home, you’d better store the fish in the refrigerator if you don’t cook it immediately, but fresh fish should be stored in your fridge for only a day or two. Frozen fish isn’t as tasty as the fresh one.
There are many common methods used to cook fish.   20   First, clean it and season it with
your choice of spices(调料). Put the whole fish on a plate and steam it in a steam pot for 8 to 10
minutes if it weighs about one pound. (A larger one will take more time.) Then, it’s ready to serve.

A:Do not buy it. B:The easiest is to steam it. C:This is how you can do it. D:It just requires a little knowledge. E:The fish will go bad within hours. F:When buying fish, you should first smell it. G:The fats in fish are thought to help prevent heart disease.

Everyone knows that fish is good for health.  16  But it seems that many people don’t cook fish at home. Americans eat only about fifteen pounds of fish per person per year, but we eat twice as much fish in restaurants as at home. Buying, storing, and cooking fish isn’t difficult.  17  This text is about how to buy and cook fish in an easy way.
18   Fresh fish should smell sweet: you should feel that you’re standing at the ocean’s edge. Any fishy or strong smell means the fish isn’t fresh.   19  When you have bought a fish and arrive home, you’d better store the fish in the refrigerator if you don’t cook it immediately, but fresh fish should be stored in your fridge for only a day or two. Frozen fish isn’t as tasty as the fresh one.
There are many common methods used to cook fish.   20   First, clean it and season it with
your choice of spices(调料). Put the whole fish on a plate and steam it in a steam pot for 8 to 10
minutes if it weighs about one pound. (A larger one will take more time.) Then, it’s ready to serve.

A:Do not buy it. B:The easiest is to steam it. C:This is how you can do it. D:It just requires a little knowledge. E:The fish will go bad within hours. F:When buying fish, you should first smell it. G:The fats in fish are thought to help prevent heart disease.

Everyone knows that fish is good for health.  16  But it seems that many people don’t cook fish at home. Americans eat only about fifteen pounds of fish per person per year, but we eat twice as much fish in restaurants as at home. Buying, storing, and cooking fish isn’t difficult.  17  This text is about how to buy and cook fish in an easy way.
18   Fresh fish should smell sweet: you should feel that you’re standing at the ocean’s edge. Any fishy or strong smell means the fish isn’t fresh.   19  When you have bought a fish and arrive home, you’d better store the fish in the refrigerator if you don’t cook it immediately, but fresh fish should be stored in your fridge for only a day or two. Frozen fish isn’t as tasty as the fresh one.
There are many common methods used to cook fish.   20   First, clean it and season it with
your choice of spices(调料). Put the whole fish on a plate and steam it in a steam pot for 8 to 10
minutes if it weighs about one pound. (A larger one will take more time.) Then, it’s ready to serve.

A:Do not buy it. B:The easiest is to steam it. C:This is how you can do it. D:It just requires a little knowledge. E:The fish will go bad within hours. F:When buying fish, you should first smell it. G:The fats in fish are thought to help prevent heart disease.

The Northern Pike is a very bad fish. It is a big, hungry fish, and swallows little fish such as trout and perch. Many Northern Pikes live in Lake Davis. They are killing all the smaller fish in the lake. The Northern Pike are a serious threat to the lake because they eat all the smaller fish. Soon, all other species of fish in the lake will be killed off. This is not healthy for the environment.
Experts are afraid that the Northern Pike will swim out of Lake Davis through many smaller rivers that feed into the lake. They could spread all over the country and damage many other water environments. If that happens, it would be too late to stop the Northern Pike.
For ten years, officials have been trying to remove the Northern Pike from Lake Davis. They haw. tried using nets, explosives and poisons. However, the Northern Pike population is still doing well in Lake Davis. Many people do not like the idea of using poison to kill the fish. They worry that the poi- sons are bad for humans who use the water. No trace of the poisons has ever been found in local wells, however.
Scientists are going to try the poison again. This time, they will drain the lake before they add the poison to the water. A public hearing will be held to talk about the problem.
Why is it a problem if all the smaller fish species die

A:It’s not healthy for the environment. B:People only like to catch big fish. C:There are too many small fish. D:The smaller fish can get lost in the lak

A dolphin(海豚)looks more like a fish than certain fishes do. It is an excellent swimmer. The dolphin seems to flash through the water. Like fish, dolphins are completely at home in the water. There they play, feed, sleep, and give birth to their young. Dolphins live in the sea and can live only in the sea.
Yet they are not fish. A dolphin must come to the surface to breathe. Fish can take oxygen from the water. Dolphins cannot. Like us, they breathe with lung and must take their oxygen from the air. And they are mammals(哺乳动物).
Most mammals are land animals. Dolphins are evolved(进化)from land animals. Long ago, dolphin ancestors(祖先)left the land for the sea. Among the animals was a kind that would become the dolphin we know. No one is sure exactly what kind of animal it was. But there is reason to think it was related to grass-eating animals like the cow. Modern dolphins are fish-eaters.Yet their stomachs are like those of animals that eat plants. The make-up of their blood is also like that of grass-eating animals.
The best title for this passage is ______.

A:Dolphins B:Fish C:Mammals D:Cows

关于FISH的叙述正确的是（）。

A:FISH是原位杂交技术的一种 B:具有荧光信号的高灵敏性和直观性特点 C:特异性好、定位准确 D:灵敏性高，与放射性探针相当 E:经济、安全、探针稳定；实验周期短