单选题 Sometimes children have trouble ______ fact from fiction and may believe that such things actually exist.
A. to separate B. separating
C. for separating D. of separating

【正确答案】 B

【答案解析】[解析] have trouble (in) doing sth. 是固定搭配，作“做某事有困难”讲，短语中介词in可以省略。例如：Andy is one of the students who have trouble making up their mind. 安迪是一个优柔寡断的学生。Northerners usually have trouble understanding the southerners' accents. 通常北方人难以听懂南方人的口音。