With the development of high technology, more and more new things ________ to the field of IT．
| A．have introduced | B．are being introduced |
| C．were introduced | D．had been introduced |
Bicycling is good exercise; ____, it does not pollute the air.
| A．nevertheless | B．besides | C．otherwise | D．therefore |
Mary is really good at taking notes in class. She can almost every word her teacher says.
| A．put out | B．put down |
| C．put away | D．put together |
When ________ questions in class, one should answer them as clearly as possible.
| A．asking | B．to ask | C．to be asked | D．asked |
It was not until I came here ____ I realized this place was famous, for not only its beauty but also its weather.
| A．who | B．that | C．where | D．before |
—How much shall I pay for the phone call?
—You________. This is free of charge.
| A．shouldn't | B．can't | C．don't have to | D．mustn't |