People should think about ________ they can have a positive influence on the planet．

A．why

B．that

C．what

D．how

The doctor advised me to go on a diet because I ________ weight during the last two months．

A．put on

B．have put on

C．had put on

D．would put on

________ her mother after being separated for 20 years, she couldn't help, even though she tried not to, ________．

A．Seen, crying

B．To see, cry

C．Seeing , crying

D．Having seen, crying

He said that not until the wheat died from the lack of water ________ how serious the drought was．

A．did the villagers realize

B．the villagers realized

C．the villagers did realize

D．realized the villagers

It's his fault, not mine．I'd shoot myself ________ I apologized to him．

A．after

B．until

C．before

D．unless

Even though it is at least 20 years ________ we got to know, I can't forget the scene ________ we were introduced to each other．

A．that , where

B．when, in which

C．since , when

D．since, where

When asked to try on new coats of different colors and styles, few men have the ________ with this treatment．

A．patience

B．interest

C．decision

D．Preference

Realizing that he would be late for school, little Tom had ________ of the bread prepared by Mum

and hurried out．

A．nothing

B．all

C．neither

D．none

________ many times, but he still doesn't know how to operate the machine properly．

A．Although I have shown him

B．I have shown him

C．Having been shown

D．Having shown

Be ready for the job interview, ________ you may miss the good opportunity．

A．and

B．then

C．or

D．so