________ cell phones bring convenience to us in our daily life, they have also caused many social problems．

Because

Whether

While

As

________ is known to us all is that the 30th Olympic Games will take place in 2012 in London．

As

Which

It

What

The new CRH train between Beijing and Shanghai ________ speed has been limited to 300 km/h focuses more on the safety of the passengers．

whose

where

that

which

Is it the fact ________ he hasn’t turned in his research report?

whether

that

which

why

Mankind must have in mind that it will be years, even centuries, ________ the environment recovers from the damage he makes to it．

that

before

when

since

Over the Huangpu River ________ four grand bridges in Shanghai so far．

have been built

have built

has been built

built

Jackson knew he would surely get ________ if he went to work late again．

shouting at

shouted at

to shout at

to be shouted at

I have tried everything I can ________ him to stay, but without success, so I wish him good luck．

persuade

persuading

to be persuaded

to persuade

He ________ as a mechanic for 10 years but now he turns businessman investing in the stock market．

has worked

had worked

worked

was working

Since 1953 ________ people all over the world have succeeded in climbing the Himalayas．

hundred of

several hundreds

several hundreds of

several hundred