由于（）的限制，球阀目前还不宜用于高温管路中。
A.制造工艺
B.密封材料
C.制造材料
D.结构
参考答案：B
The schools themselves admit that not all children will be successful in the jobs ______
they are being trained. [ ]
A. in that
B. for that
C. in which
D. for which
陈述性知识一般以()形式在头脑中贮存和表征。
A、动作；
B、表象；
C、命题和命题网络；
D、以上三者
