Bicycles have been around in our life for more than hundreds of years, but no one knows who ________ the first bicycle．

A．invented

B．had invented

C．has invented

D．would invent

Our opinions on language learning differ greatly ________ each other's in that respect．

A．at

B．by

C．for

D．from

－Have you heard of this new brand of computer, Mike?

－Yes, of course and I've decided to buy ________．

A．it

B．one

C．this

D．that

________ experiment took as five months and turned out ________ great success．

A．The; 不填

B．不填; a

C．The ;a

D．The; the

It is generally considered unwise to give a child ________ he or she wants．

A．however

B．whatever

C．whichever

D．whenever

It is not yet well understood ________ has made the rainforest disappear year by year．

A．what

B．which

C．that

D．how

Most of what has been said about the Browns ________ also true of the Dicksons．

A．are

B．is

C．being

D．to be

－Hi, Johnson, I'm thinking of taking five courts in literature next term．

－Well, wouldn't four be ________?

A．wiser

B．wise

C．the wisest

D．the wiser

As I wil be away for at least a year, I'd appreciate ________ from you now and then ________ me how everyone is getting along．

A．hearing; tell

B．bearing;to tell

C．to hear; telling

D．to hear; to tell

－What do you think of the new English teacher?

－________ she is an elegant lady, she can he extremely difficult to work witb．

A．Even if

B．When

C．While

D．Once