Do you think it is not believable to bring fish to space? Have you ever imagined raising fish in space? Recently, three astronauts from China have made it a reality!
On April 26, three astronauts in Shenzhou XVIII manned spaceship (神舟十八号载人航天飞船)successfully entered the space station. They will carry out more than 90 experiments (实验) in space, such as microgravity (微重力) in space, medicine and many other science topics.
The astronauts brought a fish tank filled with water to the space station. Four zebrafish and algae (水藻) live inside it. The algae give the fish oxygen (氧气), keeping them alive. The tank can also feed the fish, control the temperature and lighting, and collect fish eggs by itself.
Why zebrafish? Because they are quite easy to feed and they share 70% of their genes (基因) with humans. "The result of this experiment is very precious for it is China's first space-based study of water ecosystems(生态系统). Next, we plan on bringing mice to space. We'll raise them there for a while and then bring them back to Earth for further study," a professor told CCTV News. Studying animals in space can help scientists know how the human body reacts to space conditions.
The Shenzhou XVIII is expected to return to the earth after six months in space. Right now, China is going to finish picking its new astronauts. These new astronauts will join the team already working on space station tasks and help achieve China's first manned landing on the moon.
①They are easy to feed in the spaceship.
②They share over two-thirds of genes with humans.
③They can live without oxygen in the fish tank.
④They can control the temperature and lighting.
B . 
C . 
D . 
