Since humans sent the first satellite (卫星) to space in the 1950s, scientists have been studying an important topic: how to grow food in space if humans will one day live there. A recent experiment at the Tiangong space station makes a big step forward.

Chinese astronauts have successfully grown rice seedlings (幼苗) during the Shenzhou XIV mission. “The rice seedlings are growing very well,” said Zheng Huiqiong, a researcher from the Chinese Academy of Sciences.   Since the rice experiment began on July 29,the seedlings of the tall shoot rice variety (高杆水稻品种) have reached a height of 30 centimeters. The seedlings of the dwarf rice variety (矮秆水稻品种) have grown to 5 centimeters, China Daily reported on Aug 30.

While there have been other rice experiments in space, this one is the first of its kind to produce the complete life cycle of a plant-it begins with a seed and ends with a mature (成熟的) plant producing new seeds.

Such food-growing experiments are not just for astronauts. They can also solve food problems on Earth. By sending seeds to space, we can create mutated (突变的) seeds, thanks to microgravity (微重力) , lack of air and cosmic rays (宇宙射线) . The seeds can then produce higher yields (产量) on Earth.

For more than 30 years, China has developed over 260 new types of seeds in space. They are planted every year in fields that cover tens of millions of hectares (公顷) .

According to Yao Tong, an engineer from Hainan Aerospace Engineering Breeding Research Center (海南航天工程育种研发中心), 30 percent of strawberries sold in Beijing are “space strawberries”, which are as big as eggs. The center has also produced “space tomatoes” with yields increased by 30 percent, and “space bananas” with a growth cycle (生长周期) shortened from 13 months to 9 months.

After a long day’s study at school, you are very tired. So after school you go home to relax. When you get home, a robot greets you. 【小题1】 He listens to you talk about your school life and tells you a new joke. And he tells you to call your cousin and to say happy birthday. And then he helps you with your homework.

This is your future, and the robot’s name is NAO. 【小题2】 He can walk and dance. He listens and talks, and he even learns and thinks for himself. His creators (创造者) predict that the robot will be in people’s homes before 2040.

This $16,000 robot knows who you are. 【小题3】 He is a self-guided robot. A self-guided robot can sense (感觉), think and act. Other robots might do two out of the three. For example, 【小题4】 Another robot can move and sense things, but he can’t think for himself. These aren’t self-guided robots. 【小题5】

Engineers in the US have created a group of robots that are able to work together to overcome obstacles（障碍物）. “When ants collect or carry objects, if one comes upon an obstacle, the group of ants work together to overcome that obstacle,” explained Dr. Ozkan-Aydin, who led the research. “If there’s a gap（裂缝）on the road, for example, they will form a bridge by holding together so the other ants can travel across. That is the inspiration for this study.”

Ozkan-Aydin and her workmates 3D-printed a group of four-legged robots. They have touch sensors（传感器）at the front and back, so that they could sense and connect with other robots in the group. The robots were under tests of finding their way over different surfaces, including grass and rocky ground. Ozkan-Aydin also made some obstacles for them to climb up. If a robot couldn’t find its way out, it would send a signal（信号）to the other robots. Then, they would hold together with their touch sensors.

Ozkan-Aydin said this technology could be used in the future to make groups of robots to help look for people in accidents, carry things over rocky surfaces and do research in dangerous places. However, for that to become true, she says battery（电池）technology will need improving so that the robots can work for up to 10 hours without running out of power.

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