Sometimes parents find ______ hard to communicate with their children.
—The exam was very easy, wasn’t it? —Yes, but not ________ could pass it.
Wendy is my best friend. To me, our friendship is _______price.
It’s reported that several hundreds of young children have gone _________in our country, and their parents feel very sad about the _______ of them.
Ronald Amundsen is considered to be one of the greatest ________ in history because he was the first man to reach the South Pole (南极).
— Is Russia _____ European country? — Yes, though a large part of it is in _____ Asia.