18._____ arriving at the station,the Queen was welcomed by the I

18._____ arriving at the station,the Queen was welcomed by the I
A) At B) For
c) On D) In
19.Tom used to live in California,_____
A) used he B) did he
C) was he D) didn't he
20.So far there is no proof ______ people from other planets do exist.
A) which B) how
C) what D) that
21.At first I wasn't used ______ when I did something wrong.
A) to criticize B) to be criticized
C) to criticizing D) to being criticized
22.Never before ______so highly successful in changing his surroundings.
A) man has been B) man is
C) has man been D) is man
23.He often falls asleep while ______ television.
A) watching B) to watch
C) watched D) watch
24.______ from the helicopter,the city looks very beautiful.
A) Seeing B) Having seen
C) Seen D) To see
25.Not until many years later,______ known.
A) was the whole truth become B) did the whole truth become
C) the whole truth became D) the whole truth had become