参加科学拓展课的Mary观看了神舟十三号"天宫课堂"的直播，请阅读以下报道，选择正确的选项。
   The Chinese astronauts（宇航员） are so cool!They work in space.We call space "tai kong"in Chinese.So we also call the Chinese astronaut"taikonaut".On Dec.9th，Thursday afternoon，Zhai Zhigang，Wang Yaping and Ye Guangfu，three taikonauts of China's Shenzhou-13 livestreamed（网络直播） a science lesson.Look!They are the teachers in space，too.They are 400 km above the Earth（地球） in Tiangong space station.That is "Tiangong Class".
   Lots of students in China watch "Tiangong Class".They are all very excited.The taikonauts show the students how they live and work in the space station.The life in space is amazing but difficult for them.They should do exercise to keep healthy every day.In the lesson，they also show some interesting things：In space，a ping-pong ball can not float（漂浮） on the water.But the waterball can float in space.Amazing!The taikonauts also answer questions from students.They learn a lot.
   As we know，the taikonauts will come back to the Earth in April，2022.Wish them have a nice Chinese New Year's Day!
（1）--What is "taikonaut" in Chinese？
--

C

C

。
A．飞行员
B．宇航员
C．中国宇航员
（2）--Where are the teachers of this science lesson？
--They are in the

B

B

.
A．classroom on the Earth
B．Tiangong space station
C．plane
（3）--How do the taikonauts keep healthy in space？
--They

A

A

.
A．do exercise
B．drink more water
C．have a class
（4）-When will they come back home？
-

B

B

A．Jan.2022.
B．Apr.2022.
C．Dec.2021.
（5）-Which one is NOT true？
-

A

A

A．A ping-pong ball can float on the water in space.
B．The taikonauts can live in the space station.
C．The students can ask questions in the lesson.