21 You must read the ________ with great care to see if the

21 You must read the ________ with great care to see if the drug contains PPA before it's taken.
A．instructions B．explanations C．introductions D．expressions
22.Would it be ________ for you to pick me up at four o'clock and take me to the airport?
A．convenient B．vacant C．handy D．free
23．On Sunday he denied all knowledge of it,but on the day he had admitted to me that he knew all about it.
A.original B.former C.previous D.uncertain
24..He is the first drunken driver to be with “endangering public safety” and sentenced to death.
A.scolded B.charged C.criticized D.blamed
25.Once we have some knowledge,things do not become more difficult,but comprehensible.
A.acquired B .required C.inquired D.inspired 26.Some schools use only test scores to ________ their students,without taking any interest in their potential,which is wrong.
A．explain B．encourage C．evaluate D．expect
27 .Don't be by products promising to make you lose weight quickly.
A.taken off B.taken in C.taken away D.taken out
28.Though feeling a little frightened,the cat ________ a series of loud sounds,scaring the dog away.
A．let out B．left out C．left behind D．let off
29.He insisted on carrying on the experiment ________ all kinds of troubles.
A．instead of B．in spite of C．because of D．as a result of
30.—What do you think of Judy?
—There are some things about her that are not easy to________,and her coldness is one.
A．subscribe to B．put up with C．refer to D．keep up with