B
Fish babies in space? In a space study on zebrafish, Chinese had a new record. They successfully got four zebrafish to live and grow in a closed water world.
The zebrafish went to China's space station on the Shenzhou-18 spaceship on April 25. They then lived in a closed fish tank with some plants. The fish grew up and had babies in 43 days.
In their special closed water world, the plants made air for the fish and the fish's waste gave the plants food. The scientists gave the fish food through a special needle (针管).
Such a closed-loop ecosystem is important for the future study in space. It means that plants and animals can live in space more simply and easily.
The scientists also found that the zebrafish acted differently than on earth. For example, they often swam on their back. The low gravity(重力) in space is a big reason. On earth, gravity pulls everything to earth's centre, and animals can find their way easily. Gravity also makes their bodies work harder and become stronger.
Humans and zebrafish share 70% of the same genes. So the new finding will help scientists better understand human health.
(
A
) 4. What do we know about the space study?
A. It took place in a closed water world.
B. The zebrafish gave birth to four babies at last.
C. It took zebrafish less than one month to grow up.
D. Scientists from different countries did it together.
(
C
) 5. Which picture should be in the circle to show the ecosystem in the fish tank?
(
C
) 6. What was the result of the low gravity in space?
A. Human bodies got stronger.
B. Animals could easily find their way.
C. The zebrafish swam on their back.
D. The zebrafish swam in different directions.
(
C
) 7. What is the last paragraph mainly about?
A. The plan of the space study. B. The course of the space study.
C. The meaning of the space study. D. The finding of the space study.
