问题补充：
A lot of children are used to their time up by their parents and they simply don’t know with their spare time themselves.
A. have; full; what to do
B. having; filled; how to do
C. have; filling; what to do
D. having; filled; what to do
答案：
A. have; full; what to do
B. having; filled; how to do
C. have; filling; what to do
(答案→)D. having; filled; what to do
解析：考查固定词组和宾语补足语。Be used to sth/doing sth习惯于做某事/某事；what与do with连用形成what to do with 处理；当宾语their time与动词fill构成被动关系的时候，使用过去分词的形式。构成主动关系的时候，使用现在分词的形式。本的time与fill构成被动关系，故使用过去分词的形式。句意：很多学生都习惯了让父母安排好他们的时间，不知道子该如何处理他们的空闲时间。故D正确。
