--- How was your report, Sam? --- Not bad, but I need to do better in ______.

Cindy's father is a worker. He works in a __________.

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

Daniel and Simon are good badminton __________.

Bob is ___________brother.