Reading is _________.

John wants to be a     , so he often helps sick people in the hospital. 

The students  get on the bus ______        .

—You look so worried, what’s wrong?—More and more people like me become to worry about the __________ pollution  after the haze (雾霾) appeared in Beijing and some other cities in China.

Mrs Smith lives in our building. She is really a good        because she is always ready to help people around her.