精神分裂症最具特征性的症状是思维联想过程缺乏_____________和_____________。
参考答案：连贯性；逻辑性
When asked to explain ________ made his lessons so exciting, the teacher kept silent.
A．what it was that
B．that what it was
C．what was it that
D．that what was it
悬挂风筒的拉线至少每隔（）m进行一次固定，拉线要与巷道坡度一致，风筒吊挂高度不低于1.6m。风筒吊挂要平、直、稳，要逢环必挂，吊挂材料要相同，吊挂方式要统一，30m长度内高低差不大于50mm。
A、20m
B、30m
C、50m
