____, he does not know the answer.
| A．As he is a teacher | B．As he is teacher |
| C．A teacher as he is | D．Teacher as he is |
citizen
| A．uncle | B．ocean | C．rescue | D．percent |
laugh
| A．daughter | B．neighbour | C．enough | D．though |
Not once ________ to Michael that he could one day become a top student in his class.
| A．occurred it | B．it did occur | C．it occurred | D．did it occur |
— I don’t understand why you didn’t go to the lecture yesterday afternoon.
—I’m so sorry. But I _________ my homework.
| A．had done | B．was doing | C．would do | D．am doing |
The university estimates that living expenses for international students ________ around $8,450 a year,
which ________ a burden for some of them.
| A． | are；is | B． | are；are | C． | is；are | D． | is；is |