单选题 ______ animals must be kept in cages in case they might hurt the tourists.
A. Land B. Domestic C. Vicious D. Farm

【正确答案】 C
【答案解析】vicious凶恶的；不道德的，堕落的；land陆地，国土；domestic家庭的；国内的；驯服的；farm农场，农田。