单选题 The monks let ______ outside their enclosures, and then they have great freedom too.
【正确答案】 C
【答案解析】[解析] 本题测试使役动词。我们将let/make/have…这一类词称为使役动词，其后的动词不定时要省略to。如：Let's go. His story made us laugh to tears. 所以C选项是正确答案。其他选项均不符合该语法规则。