The computer center, ________ last year, is very popular among the students in this school．

A．open

B．opening

C．having opened

D．opened

________ more attention, the tree could have grown better．

A．Given

B．To give

C．Giving

D．Having given．

Don’t use words, expressions or phrases ________ only to people with specific knowledge．

A．being known

B．having been known

C．to be known

D．known

Laws that punish parents for their little children’s actions against the laws get parents ________．

A．worried

B．to worry

C．worrying

D．worry

It was so large a room that a hundred people looked ________ in it．

A．losing

B．lost

C．to lose

D．having lost

From the dates ________ on the gold coin, we decided that it was made five hundred years ago．

A．marking

B．marked

C．to be marked

D．having been marked

Linda worked for the Minnesota Manufacturing and Mining Company(明尼苏达州矿业与制造公司), ________ as 3M．

A．knowing

B．known

C．being known

D．to be known

Is this the bike which you wish to have ________?

A．repaired it

B．repairing

C．repair

D．repaired

Every possible means ________ to prevent the air pollution, but the sky is still not clear．

A．are being used

B．have been used

C．has been used

D．had been used

He’s ________ to fail the exam if he doesn’t do any revision．

A．near

B．fit

C．bound

D．easy