—           .You'd better see a doctor at once.

I really don't know what   to help her out.

 her father  her mother is very pleased with her Chinese.

Sandy did her homework watching TV last Sunday.

The teacher told the children cheat in exams.

How cool would it be people could travel in tubes(管道)? They may travel to another city in just (minute). In the near future, this might happen not only in movies, also in real life. The first open-air test of the tube train took place May 11. It happened in the Nevada Desert, the US. Elon Musk (have) the idea of developing(开发) the tube train. He is the founder (创始人) of the US space company SpaceX. He calls the tube train the Hyperloop. The Hyperloop will be even (fast) than the plane. It (go) about 1,200 kilometres per hour. Planes usually (fly) 800 to 1,100 kilometres per hour. The company Hyperloop One is still (work) on the tube train. They want people travel using the Hyperloop by 2021.