His assignments are always extremely hazardous. Last month he was assigned to detect the hidden mines. This month he will lead a patrol behind enemy lines.

A．dangerous

B．varied

C．exciting

D．lengthy

I found a secluded area where no man or animal could be seen for miles around.

A．cool

B．isolated

C．quiet

D．noisy

An occasional respite during a long evening of study is desirable. Tom often takes a short breather between chapters or between assignments.

A．test

B．review

C．drink

D．rest

He felt very alone; he had lived in Baltimore City for a month and had met no one in the inhospitable city.

A．unfriendly

B．uncomfortable

C．unhealthy

D．enormous

Things are not always ________ they seem to be.

A．as

B．the same

C．that

D．how

Do you think ________?

A．it true what he said

B．what he said is true

C．it is true what he said

D．what did he say is true

Good technique in medicine means less pain and fewer death, and ________ it is our duty to master it.

A．altogether

B．therefore

C．otherwise

D．however

Many people are still in ________ habit of writing silly things in ________ public places.

A．the; the

B．不填; 不填

C．the;不填

D．不填; the

——Has John come here?

——No, but he promised to ________ me at my house at nine.

A．call at

B．send for

C．call for

D．call in

They seldom ________ in bed after 5:00 a. m. even though they were on holidays.

A．remained

B．slept

C．was

D．continued