31. The men will have to wait all day ___________ the doctor works faster.
A. if B. unless C. whether D. that
答：B. unless相当于正if...not ...。
32 —Did you remember to give Mary the money you owed her?
—Yes, I gave it to her_________ I saw her.
A. while B. the moment
C. suddenly D. once
答：B. the moment (second, minute, instant), directly, immediately相当as soon as之用法。如：
Directly he comes, I’ll tell him the news.
The minute I see him, FII tell him the news.
33. Excuse me for breaking in, ________I have some news for you.
A. So B. and C. but D. yet
答：C。 Excuse me...but...为常用句型。如：Excuse me, but could you tell me the way to the railway station?
34. —Was his father very strict with him when he was at school?
—Yes. He had never praised him__________ he became one of the top students in his grade.
A. after B. unless
C. until D. when
答：C．not (no, never) ...until...直到……时才……。unless 与 if...not...意思相符，但若使用unless (if...not), 一般用虚拟语气，主句应是He would never have praised him if he had not become one of the top students in his grade 或He would never praise him if he did not become one of the top students in his grade.
35. John shut everybody out of the kitchen ____ he could prepare his grand sur-prise for the party.
A. which B. when
C. so that D. as if
答：C．so that引导目的状语从句，意为“为了给晚会准备一个惊喜”。
36. —Would you like to come to the dinner party here on Saturday?
—Thank you. I’d love to, __________ I’ll be out of town at the weekend.
A. because B. and
C. so D. but
答：D。前后两句明显看出是转折关系。
37. Excuse me for interrupting you, ___________I have some questions to ask.
A. so B. and C. yet D. but
答：D。Excuse me...but...为常用句式(见33题解析)。
38. I had just started back for the house to change my clothes _________ I heard voices.
A. as B. when C. after D. while
答：B。when 就在那时。如：I was just about to go out when the phone rang. 正要出去，(就在那时)电话响了。
39. I have a car. I can take you __________ you want to go.
A. whenever B. wherever
C. however D. whichever
答：B．wherever 无论何处
40. He was about to tell me the secret __________ someone patted him one shoulder.
A. as B. until
C. while D. when
答：D。when就在那时．如：I was walking down the street when I heard my name called! 我正在沿街走时听到有人叫我的名字。
41. Sally worked late in the evening to finish her report _________her boss could read it first thing next morning.
A. so that B. because
C. before D. or else
答：A。在这里sothat引导的是目的状语从句。so that引导的从句中若没有情态动词will, would, may, might, can, could等词，so that从句就是结果状语从句。如：started out very early so that ! caught the first train. 我很早就出发了，结果我赶上了第一班列车。or else否则。
42. Mr Hall understand that __________ math has always been easy for him, it is not easy for the students.
A. unless B. since
C. although D. when
答：C。从句中easy...not easy重要的信息词可知。