Mr. Smith a novel last year but I don't know whether he has finished it．（ ）
| A． |
wrote |
| B． |
was writing |
| C． |
has written |
Grandmother lives with my parents． They _____ her every day．（ ）
A．look atB．look afterC．look for
I _____ some washing when you called me last night．（ ）
A．was doingB．am doingC．were doing
Dad， I want to be a policeman in the future．
Work hard， _____ you will succeed．（ ）
A．orB．andC．but
_____ the mountain is， _____ the air is．（ ）
A．The highest， the thinnest
B．Higher， thinner
C．The higher， the thinner
It _____ me two hours to help Mary with her math last Saturday．（ ）
A．tookB．spentC．paid