–I find Chinese people are helpful when traveling around China. –You’re right. I like ______ when people are friendly and helpful.
All his free time is ______ by volunteer work, but he feels it meaningful.
The athletes competed ________ each other for gold medals in the Olympic Games.
--Can a plane fly ________ the Atlantic Ocean? --Yes, but it needs to go________ the clouds for hours.
The room ___________ window is open is mine.
Don’t turn on the radio __________ your mother allows you.