[例1]—Do you think it’s going to rain over the weekend？
—______.
A.I don’t believe B.I don’t believe it
C.I believe not so D.I believe not
【解析】答案D。“so”可代替某些動詞後的賓語從句，但絕不能用it或that。這些常用的動詞有：believe，be afraid，expect，hope，imagine，suppose等。例：
—Is she going to the party tonight？
—I think so./I hope so.
其否定有兩種：
1.動詞用否定結構。
2.用not代替so。如：
—Do you think he will pass the exam？
—I don’t think so./I think not.前者更常用。
錯解分析：A項應為I don’t believe so。C項否定也應否定謂語。
解題方法與技巧：根據具體語言環境，正確運用表達觀點的方法。
[例2]______for the free ticket，I would not have gone to the films so often.
A.If it is not B.Were it not
C.Had it not been D.If there were to
【解析】答案C。跟過去事實相反的虛擬條件句結構為If+主語+had+過去分詞，主語+would/could/might do…當if省略時，將had提主句首，即
Had+主語+過去分詞，主語+would/could/might do…
錯解分析：
A項不是虛擬語氣結構。
B項是跟現在事實相反的虛擬條件句。
D項是跟將來事實相反的虛擬條件句。
[例3]—You ought to have given them some advice.
—______，but who cared what I asked？
A.So it was B.So I ought to have
C.So I did D.So I ought to
【解析】答案B。ought to，want，hope等動詞後可省略作賓語的不定式短語，但該賓語若是be動詞或動詞的完成時，則需在to後加be或have。
—Are you a soldier？
—No，but，wish to be（a soldier）.
[例4]The research is so designed that once______nothing can be done to change it.
A.begins B.having begun C.beginning D.begun