Scientists generally agree that earth’s climate will warm up over the next 50 to100 years______ it has warmed in the 20,000 years since Ice Age.
A. so long as. B. as much as C as long as. D as well as
The manager meant ____ the workers that being 5 minutes late meant ____ the company.
| A．to tell, to leave | B．telling, leaving | C．to tell, leaving | D．telling, to leave |
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