Look out！Don’t get too close to the house ________ roof is under repair．
| A．which | B．whose |
| C．what | D．that |
The students were ____ over the ____ problem, listening to the teacher with a ____
expression on their faces.
| A．puzzled; puzzling; puzzling | B．puzzled; puzzling; puzzled |
| C．puzzling; puzzling; puzzled | D．puzzling; puzzled; puzzling |
The reason for his success is ______ he has worked very hard.
| A．why | B．that | C．whether | D．how |
The weather turned out to be fine yesterday. I_____ the trouble to carry my umbrella with me.
| A．should have taken | B．could have taken | C．needn't have taken | D．mustn't have taken |
I was about to leave the office ______ an unexpected visitor came.
A. while B. as C when D. before
It was a matter of ________ would take the position.
| A．who | B．whoever | C．whom | D．whomever |