Question

It may seem like a moment in a science fiction movie. In a fierce battle, a creature loses an arm but, then, grows another one to take its place.

However, this is not science fiction. It is scientific fact. Some fish and amphibians, such as salamanders, can regrow lost limbs and organs.

As mammals evolved they lost the ability to regrow, or regenerate, parts of their body. However, experiments show that it may be possible to regain that ability.

Tropical freshwater zebrafish are popular pets. They are also popular as lab animals. Their embryos(胚胎) are clear, or translucent. They can regrow damaged fins, skin and hearts. Zebrafish are also genetically（基因地） similar to humans.

In 2013, the website Sci-News reported that researchers had found that 70 per cent of “protein-coding human genes” are related to genes found in the zebrafish. The report also said that researchers at the Wellcome Trust Sanger Institute in Britain also found that 84 per cent of genes known to be connected to human disease have a zebrafish counterpart.

Scientist Wang Yadong is one of the Pittsburg researchers. He and his team are studying the ability of zebrafish to regenerate limbs and organs. Wang says you can cut away about 20 per cent of the zebrafish heart and it will regenerate. He add that same process may be able to help humans.

Scientists injected（注射） an “extracellular matrix,” or ECM, from the heart of a zebrafish into a severely damaged mouse heart. They found that the heart muscle regrew in days. They found something else. The healing was even faster when the ECM was taken from zebrafish that was itself in the process of re-growing damaged tissue.

1.The main reason why the zebrafish were chosen as lab animals is that _____________ .

A. they are popular pets

B. their bodies are clear to study

C. they are genetically similar to humans

D. they are easy to find for the researchers

2.What does the underlined word “counterpart” in Paragraph 5 probably mean?

A. A similar thing.

B. A different fish.

C. A human being.

D. A little mouse.

3.After injecting ECM from a zebrafish into the damaged mouse heart, what did scientists find?

A. The zebrafish died quickly.

B. The mouse heart regrew in days.

C. The zebrafish heart regrew quickly.

D. The mouse healed more slowly than normal.

4.Where is the most probably taken from?

A. A science fiction.

B. A guide book.

C. A fashion magazine.

D. A science report.

Answer 1