1. In ancient China, people used to send smoke _____ to warn that the enemy were coming. A. signs B. signals C. symbols D. marks 答案: B来源：考试大 解析: 这个题考四个名词的比较, 其中: signs 迹象. signals 信号. symbols 象征. marks 分数. 2. The icy conditions made our travel dangerous. So _____ going by car we took the underground. A. instead of B. in addition to C. as well as D. at the cost of 答案: A 解析: instead of 代替,而不是. in addition to 除了…之外(还有). as well as 也(除…之外), 既…又…. at the cost of 以…为代价. 这道题横线后面是动名词形式,所以选项C和D首先排除. 3. Sometimes my job is boring, but _____ I enjoy it. A. by contrast B. by nature C. on the whole D. on the average 答案: C 解析: by contrast 与…相比,后面要跟with, by contrast with与…相比较. by nature 本性,生性. on the whole 总的来说. on the average 平均. 4. I’ll buy the clock _____ it costs. A. what B. whatever C. where D. however 答案: B本文来源:百考试题网 解析: 不管花多少钱,我都买下这个钟. 5. _____ Mr.Wilson is well again, he can travel. A. Now that B. So far C. Though D. Even if 答案: A 解析: Now that 既然. So far和现在完成时态连用.