1 . By the end of last year, 10,000 trees________ ( plant ) in that village. （所给词的适当形式填空）

2 . By the time he died in 2016, Ali ________ (recognize) as one of the greatest boxers of all time.（所给词的适当形式填空）

3 . The illegal case ________ for several weds and finally the police reached a conclusion.

A．was investigated	B．has been investigated
C．had been investigated	D．will be investigated

4 . By the time the city half-marathon began, all potential problems ________(handle) carefully. (所给词的适当形式填空)

5 . When my breathing returned to normal, I reflected on what __________ just __________ (achieve). (所给词的适当形式填空)

7 . The classroom ________(clean) before the teacher came, so the floor and windows are very clean. (所给词的适当形式填空)