[例1]—— Did that book give the information you needed？
—— Yes，but______，we had to read it almost entirely.
A.for finding it B.to find it
C.finding it D.by finding it
【解析】答案B。不定式“to find it”作目的狀語，“為了找到需要的信息，我們不得不把整本書讀一遍”。
[例2]Charles Babbage is generally considered______the first computer.
A.to invent B.inventing
C.to have invented D.having invented
【解析】答案C。“通常人們認為是Charles Babbage發明了第一台計算機”，不定式“to have invited”作主語補足語。
[例3]There isn’t any difference between the two.I really don’t know____.
A.where to choose B.which to choose
C.to choose what D.to choose which
【解析】答案B。“這兩者沒有什麽區別，我真的不知道選擇哪一個”，不定式to choose作know的賓語。
[例4]What the scientist said greatly encouraged us______the experiment again，but his secretary’s words discouraged us______the experiment any more.
A.to try；to do B.to try；from doing
C.for trying；from doing D.trying；to do
【解析】答案B。“鼓勵某人做某事”，用encourage sb to do sth.所以，第一個空填to try；相反，“不鼓勵某人做某事”，用discourage sb from doing sth。
[例5]She felt it a great shame______so severely in the presence of her boy friend.
A.to criticize B.to have criticized
C.to be criticized D.to have been criticized
【解析】答案D。“她感覺在男朋友麵前遭受如此嚴厲的批評真是一種恥辱”，不定式完成被動形式“to have been criticized”在此作賓語補足語。
[例6]John was made______the truck for a week as a punishment.
A.to wash B.washing C.wash D.to be washing
【解析】答案A。“他被懲罰洗卡車一周”，“to wash”作主語補足語，原本是“make sb do sth”句型，在這用被動語態，不定式需要加不定式符號“to”。