石门和立井揭煤工作面煤体()适用于松软煤层,用以增加工作面周围煤体的强度。
A、强化措施
B、固化措施
C、加固措施
D、硬化措施
参考答案:B
There was never any time for Kate to feel lonely, _____ she was an only child.[ ]
A. ever since
B. now that
C. even though
D. even as
铸造全冠试戴时,固位差的原因,不正确的是().
A.未完全就位
B.龈距短
C.聚合度大
D.代型上的间隙剂过厚
E.石膏代型磨损