Ⅰ.单项填空(共15小题；每小题1分，满分15分)
请认真阅读下面各题，从题中所给的A、B、C、D四个选项中，选出最佳选项。
1．“Spittake” refers to an act ________someone spits liquid out of his or her mouth ________he or she hears something funny or surprising.
A．where; in which B．in which; when
C．when; in which D．in which; where
解析：选B 考查定语从句和状语从句。句意：“笑喷”一词指的是一种行为，即当人们听到滑稽或令人惊讶的事情时将液体从口中吐出。第一空是定语从句的用法；第二空后是时间状语从句。
2．Ensuring that animals _______not isolated ________thought to be another major point of quality in assessing a zoo.
A．are; is B．is; are
C．is; is D．are; are
解析：选A 考查主谓一致。句意：确保动物不被孤立被认为是评估动物园的另一个主要质量因素。第一空用are作宾语从句主语animals的谓语动词；第二空是动名词短语ensuring that animals are not isolated作主语，用单数形式。因此选A。
