新概念第一册L143-144练习,

He _has been taught_ (teach) English by Mr.Priestley for three years.
That mistake_must be corrected_(must correct) immediately.
I know that bridge_was built_(build) during the war.
We _haven't seen_ (not see) Tom since last Sunday.We don't know where he_is_(been).
While Tom_was/is reading_(read) a newspaper,his son_was/is watching_ (watch) television.
If the car_cannot be repaired_(not repair),I shall buy a new one tomorrow.
The thief_hasn't been caught (not catch) yet,but I'm sure he_will be caught_ (catch) soon.
Mr.Smith_will/is going to seel_(sell) his house if he retires next month.

这二课文讲得最多的时态是被动时态。