单选题 It is reported that crimes are most likely to happen in cities ______ a large percentage of unemployment.

【正确答案】 C
【答案解析】本题测试定语从句。that 在定语从句中作主语,其先行词为 cities。虽然 where 能修饰 cities,但它不能在句中作主语。本句大意:据报道这些犯罪活动很有可能发生在失业率比较高的城市。