4. He does not _______as a teacher of English as his pronunciation is terrible .
A.equal
B.match
C.qualify
D.fit
参考答案：C
解析：正确答案选C。(A) equal作动词用时意为"等于，比得上"。(B)match："与……相匹敌，使较量"。(C)qualify："有资格"。(D)fit："使合适，使符合"。根据句意，应选(C)qualify。全句的意思是：他当英文教师不够资格，因为他的发音糟透了。
5. Dozens of scientific groups all over the world have been _______the goal of a practical and economic way to use sunlight to split water molecules.
A.pursuing
B.chasing
C.reaching
D.winning
参考答案：A
解析：正确答案选A。goal只与四个备选答案中的(A)pursuing："追求，寻求"和(C)reaching"达到"相搭配，故(B)chasing："追逐"和(D)winning："赢得"应立即排除。由于(C)reaching (the goal)指已达到的目标，实际上句中所说的"利用太阳光分裂水分子"的方法仍在摸索中，尚未变成现实，故(C)也应排除。(A)pursuing指正在"寻求"达到上述目标的方法，符合句意，故(A)为正确答案。
6. The discussion was so prolonged and exhausting that _______the speakers stopped for refreshments .
A.at large
B.at intervals
C.at ease
D.at random转自学易网 www.studyez.com
参考答案：B
解析：正确答案选B。(A) at large："自由行动，消遥自在地"。(B)at intervals："不时，时时"。(C)at ease："不紧张，自由自在"。(D)at random："随便，随机的，随意的"。根据句意应填(B)。全句的意思是：讲座会开得那么冗长使人精疲力尽，致使发言的人不时停下来喝点饮料。refreshments也可作"点心"解。