21.The ________all demanded to see the manager at once.
   A involving people               B involved people
   C people involving               D people involved

22. — Do you think the Stars will beet the Bulls
—Yes.They have better players, so I _______ them to win.
A.hope         B.prefer             C.expect              D.want

23. They _______ the train until it disappeared in the distance.
A.saw         B.watched           C.noticed              D.observed

24. She _______ his number in the phone book to make sure that she had got it right.
A.looked up    B.looked for          C.picked out           D.picked up

21. 正確答案：D
  例題解析：people involved 意為相關的人， 單個的過去分詞作定語一般放于被修飾詞后面，

22. 正確答案：C
expect期望.我期望他們贏.hope后面不能接動詞不定式作賓補.want想,表示個人的欲望;prefer更喜歡,構成prefer to do sth.,prefer doing sth.to doing sth.,prefer to do sth.rather than do sth.等短語.

23. 正確答案：B
watch注視.他們注視著火車直到它消失在遠方.

24. 正確答案：A
look up查找,查尋;look for尋找; pick out挑出來;pick up拾起.她在電話簿是查找電話號碼,要用looked up.