1题完成句子；2、3题简略回答问题；4题找出并写下最后一段的主题句；5题将文中划线句子译成汉语。At 15:40 on December 9th, 2021, the "space teacher", Wang Yaping, made some experiments in the Tianhe Core Module of the Chinese Space Station.
"Welcome to the ‘Tiangong Classroom!' " said Wang Yaping.
Taking a "spacewalk" is difficult. Ye Guangfu was working hard to walk, but his body floated! Then he tried to turn around but he couldn't. "In space, astronauts are in a weightless environment. So we need to use nearby devices (装置) to move," he said.
The paper flower "blooms". In the "Tiangong Classroom", Wang Yaping made a beautiful water film (水膜). Then she took out a paper flower and placed it on the film of water. The pink flower slowly "bloomed"! "I hope your dreams can bloom in the huge universe!" she said.
"Space Happy Ball" rings fun. Wang Yaping asked the children on the ground to put their ping pong ball in the water. The density (密度) of the ball was less than that of the water, so it floated up. In space, when she put the ping pong ball into the water, it did not float up to the surface. It stopped in the center of the water! "The buoyancy (浮力) disappears in a weightless environment in space so the ping pong ball cannot float (漂浮)." Ms. Wang explained.
