The black box is a necessary device on an airplane, which records its speed, direction and whether everything on the airplane_____normally.[ ]

Chan’s restaurant on Baker Street, ______ used to be poorly run, is now a successful business.

According to my grandma，it is a good idea to eat chicken soup when you have a cold—________，scientists agree with her

Do you know Tan Dun makes his music Water without any instruments一Really amazing music he has created!

I_______ the piano for two years.