he field research will take Joan and Paul about five months; it will be a long time _______ we meet them again.
| A．after | B．before | C．since | D．when |
— How much do you know about the 3D film technology?
— A little. Not until ________ the hot movie Avatar ________ some about it.
| A．did I see; did I begin to learn | B．I saw; I began to learn |
| C．I saw; did I begin to learn | D．did I see; I began to learn |
The hard life in the mountainous area he has adapted to ____ a real challenge to anyone.
| A．mean | B．means | C．meant | D．meaning |
The process of producing electricity may also give out CO2, ______ you heat your house with electricity instead of charcoal.
| A．as long as | B．as soon as | C．as if | D．even if |
---Why was the young lady taken away by the police?
---- She happened _______ something in the supermarket.
| A．to catch stealing | B．to catch to steal |
| C．to be caught stealing | D．to be caught to steal |
The project is based on an agreement, one of _____ purposes is to ensure that the project can be completed before the deadline.
| A．whose | B．which | C．its | D．what |