All the volunteers were very tired, but ofthem took a rest.—They were busy looking for the missing people.

Was the driving pleasant when you went to Mexico last summer? —— No, it ＿＿＿＿ for four days when we arrived, so the roads were very muddy

Stephen Hawking believes that the earth is unlikely tobe the only planet _______ life has developed gradually.

Have you finished your homework—Not _____. There are still some exercises to be done.

下列各句中，没有语病的一项是