—Why do you look so puzzled?
—Oh，I ________ over a most difficult maths problem.
| A．thought | B．have thought |
| C．am thinking | D．think |
Oh, dear. I forgot the two _________.
| A．room’s number | B．rooms’ number | C．room numbers | D．rooms’ numbers |
She has been in Tianjin for ten years. Tianjin has become her second _________.
| A．family | B．house | C．home | D．room |
________ mothers couldn’t go to the meeting, because they have gone to Shanghai .
| A．Mary and Peter’s | B．Mary and Peter |
| C．Mary’s and Peter | D．Mary’s and Peter’s |
Li Lei has been to __________ many times this month.
| A．her uncle | B．her uncle’s | C．her uncles | D．aunt’s |
He is a success as a leader but he hasn’t ________ in teaching.
| A．many experiences | B．much experience |
| C．an experience | D．a lot experience |