Now the Internet is a popular channel _________ the public voice their opinions and show their strength．

A．by that

B．through which

C．through that

D．by which

Since the opening and reform policy, China _________ a boom in its economy．

A．enjoys

B．has been enjoying

C．enjoyed

D．having enjoyed

_________ private cars are bringing us conveniewce, they may also cause traffic accidents and pollution．

A．When

B．Since

C．While

D．As

Nowadays, many people walk to work, _________ Copenhagen(哥本哈根)Conference calling for living a low-carbon life to cope with global warming．

A．in relation to

B．in terms of

C．in apposition to

D．in response to

He has been working hard day and night, which, of course, _________ his tiredness．

A．accounts for

B．answers for

C．applies for

D．stands for

Could I do some explanations? I _________ to call on you last night, but somebody came to see me just when I was to about leave．

A．would intend

B．intended

C．had intended

D．was intending

His parents, _________, didn’t look after him very well－the elbows of his jacket and his boots were badly worn out．

A．generally

B．apparently

C．gradually

D．precisely

After months of voyage, Columbus arrived in _________ later proved a new continent．

A．what

B．where

C．that

D．which

_________ delicious, the food was soon sold out．

A．Being tasted

B．Having tested

C．Tasting

D．Tasted

Nobody witnessed the accident, so people reached a _________ conclusion about the possible cause of the accident．

A．alternative

B．brilliant

C．competent

D．tentative