He tried his best to solve the problem, _______ difficult it was.
| A．however | B．no matter | C．whatever | D．although |
— ________?
—No, you have to pay for them.
| A．Are the drinks free | B．Do the drinks cost much |
| C．Are the drinks expensive | D．Do I have to pay for the drinks |
Is this the reason at the meeting for his carelessness in his work?
| A．he explained | B．what he explained |
| C．how he explained | D．why he explained |
It’s freezing outside. You ______put on your coat.
| A．had better to | B．had better | C．would rather | D．would better to |
Jack asked his brother Betty.
| A．did he know | B．if he knows | C．does he know | D．whether he knew |
I have heard from my father, is in American.
| A．which | B．that | C．from whom | D．who |