角色游戏
参考答案：
儿童以模仿和想象，通过扮演角色，创造性地反映周围生活的一种游戏。
Evidence has been found through years of study ________ children's early sleeping problems are
likely to continue when they grow up. [ ]
A. why
B. how
C. whether
D. that
钢丝绳端部固定应选用与钢丝绳（）相应的压板、锲形套、锥套、绳卡、压制接头等固定。
A、数量
B、长度
C、直径
D、类型
