Ⅰ.单句语法填空
1．Where have you been？We have been looking(look) for you everywhere.
2．They have known (know) each other since childhood.
3．I have been trying (try) to get my new room in order all morning.
4．Sorry，I'm full.I have had (have) supper already.
5．—He hopes that he will find a job tomorrow.
—Well，it is said that he has been looking (look) for a job for three months.
6．Maria has been learning/has learned (learn) English for two years and she does well in it.
7．Some scientists have been doing (do) research on artifical internal organs.
8．All these years they have been contributing (contribute) articles to our magazine.
9．The little boy is dirty all over because he has been playing (play) in the mud all morning.
10．Here he is! We have been waiting (wait) anxiously for him since last night.
