Why are you walking so quickly, Edward?—There_____ a talent show in ten minutes.

According to the recent research, heavy coffee drinking and heart attack is not necessarily ______ and effect.

More than two _______years ago, people knew little about the universe.

_____ do they want to join?—Music club.[ ]

Many teenagers show interest in the books that are written ________ Guo Jingming.—That’s true. My son says he can get what he thinks and wants in his books.[ ]