I think it's really ______ hard work for me to finish the job in ten minutes．（ ）
| A． |
a |
B． |
an |
C． |
the |
D． |
不填 |
It's already tens of years____the world's population reached five billion．（ ）
| A． |
before |
B． |
after |
C． |
since |
We must remember____．（ ）
| A． |
what our teacher said |
| B． |
what did our teacher say |
| C． |
what has our teacher said |
We don't know if our friend ____．If he____，we'll let you know．（ ）
| A． |
comes；comes |
| B． |
comes；will come |
| C． |
will come；comes |
It's getting dark．You'd better ____out by yourself．It's dangerous．（ ）
| A． |
not go |
B． |
not to go |
C． |
to go |
Look out!The food on the plate smells____．You can't eat it．（ ）
| A． |
badly |
B． |
bad |
C． |
good |