The defense computers calculate ways to______the enemy missiles

A．their

B．their one

C．theirs

D．they

A．However he is old

B．Old as he is

C．He is as old

D．As old he is

A．educational

B．political

C．commercial

D．social

A．The honey-bee is blind to red.

B．Man is more color-conscious than the honey-bee.

C．The honey-bee can see far more colors than man.

D．Man is sensitive to the ultraviolet.

A．which

B．where

C．that

D．when

A．gives up

B．eats up

C．takes up

D．breaks up

A．in

B．off

C．out

D．on

A．to write about

B．to write with

C．to write

D．to write in

A．At times

B．At a time

C．At all times

D．At no time

A．Possibilities

B．Chances

C．Possible

D．Probabilities