用所给词的适当形式填空。

（1）We (know) each other for two years.

（2）We (learn) more than l,000 new words since we (come) here.

（3—）How long you (be) in America?

      —For about ten years.

（4）The old man works very hard. He (plant) about 200 trees on both sides of the road this year.

（5）—When you (see) her?

         —To be honest, I (not see) her since she left our hometown.

（6）I (have) three pieces of bread, but I want (have) another one because it is very delicious.

（7）—Mum, I (finish) my homework. May I (go) out to play with my friends now?

        —Of course.