________ you are aware of the trick used in advertisements, I don't think you are eager to buy．

A．Whether

B．Until

C．Though

D．Once

She remembered several occasions in the past ________ she had experienced a similar feeling．

A．which

B．where

C．what

D．when

One thousand dollars a month is not a fortune but will help cover my living ________．

A．bills

B．expenses

C．prices

D．charges

Almost everybody has sensed that Dave cares most about money ________ the surface．

A．under

B．behind

C．beneath

D．below

Schools have rights to ________ their own rules based on the general conditions of the students．

A．make out

B．put up

C．set out

D．make up

While our city tries impatiently to change its appearance by tearing down old buildings, more and more citizens are suggesting ways to ________ the historically important architecture．

A．decorate

B．develop

C．preserve

D．reserve

I don't think the experiment is ________ failure．At least we have gained ________ experience for future success．

A．/; the

B．a; the

C．/;/

D．a;/

Every time ________ they met, they would talk several hours together about all of the situations ________ appear in the working world．

A．that; when

B．when; where

C．which; what

D．/; that

It ________ we had stayed together for several weeks ________ I found we had a lot in common．

A．was until; when

B．wasn't until; that

C．wasn't until; when

D．was until; that

You ________ all those calculations! We have a computer to do that sort of thing．

A．needn't have done

B．must not have done

C．shouldn't have done

D．can not have done