In the botanic garden we can find a(n)______of plants that range from tall trees to small flowers.
Between the two generations, it is often not their age, _________ their education that causes misunderstanding.
—Can’t you read the sign, sir? No parking here! —_____.
_____ U2, the Irish rock band from Dublin perform a concert in Beijing, tell me in advance.
They only say such unkind things about you out of ____ envy, because you are ____ success as a writer.
____ the police know the killer's identity, they are getting close to catching him.