People sell their products ____advertisement in the newspaper.
| A．by putting an | B．to put an |
| C．by putting a | D．putting an |
I was reading attentively in my own room ________ suddenly he knocked at the door.
| A．when | B．while | C．then | D．as |
He has five___________ , and they are all doctors working in the same hospital .
| A．sons- in-laws | B．son-in-laws | C．sons-in-law | D．son in laws |
I’ll go to fight in the battle __________ you go or not .
| A．no matter | B．whether | C．even though | D．if |
There are countless ________ leaves as if they were a red blanket_______ the ground.
| A．fallen; covering | B．falling; covered |
| C．fallen; covered | D．falling ; covering |
he has been working so hard . __________ he could answer such a difficult question.
| A．No wander | B．No wonder | C．why | D．because |