>
B. Though; but
C. Though; yet
D. Even; still
答案C。Although /Though和but都是连词，在一个句子中，只能使用一个，不可同时使用。这里的yet充当副词。同样的道理，because和so，一“因”一“果”，也不能同时在一个句子中使用
3. 连词从语法作用上说，有并列连词，即连接并列的词、短语或句子，表示并列、递进、转折、因果、选择等等，如and, but, or, nor, so, therefore, yet, however, nevertheless, for, as well as, both…and…, not only…but also…, either…or…, neither…nor…, and then等；
例一Stand over there you’ll be able to see it better.
A. or B. while
C. but D. and
答案D。and表示递进。
例二 You have failed two tests. You’d better start working harder, ____you won’t pass the course.
A. and B. so
C. but D. or
答案D。or引出结果。
例三—— I think George doesn’t really care for TV plays.
——Right, he still watches the program.
A. and B. but
C. or D. so
答案B。but表示转折。
例四Unlike watching TV, reading is a highly active process ______ it requires attention as well as memory and imagination.
A. until B. but
C. unless D. for
答案D。for表示因果。
连词还有从属连词，即连接复合句中的主句及从句。其中：
（1） 引导名词性从句的连词有：
①连接陈述句，表示事实的连词that；
例 A story goes ______ Elizabeth I of England liked nothing more than being surrounded by clever and qualified noblemen at court.
A. when B. where
C. what D. that
答案D。
②连接一般疑问句，表示是否的if或whether；
例 ________ we will build a new power plant hasn’t been decided yet.
A. If B. what
C. whether D. that
答案C。whether引导主语从句，表达是否之意，使用whether，不能用if。特别提醒：在名词从句中，只有及物动词的宾语从句可以同时使用if来引导，其他情况都要用whether来引导。
③连接特殊疑问句，表示“5W1H”的who, whose, what, how, where, when, why等。
例一 After Yang Liwei succeeded in circling the earth, ___ our astronauts desire to do is walk in space.
A. where B. what
