焦炭与CO2或（）的能力称为焦炭的反应性。
参考答案：水蒸汽相作用
铸造金属全冠牙体预备时，牙合面应磨除（）
A.0.3～0.5mm
B.0.6～0.7mm
C.0.8～1.0mm
D.1.2～1.5mm
E.1.5mm以上
There is a river ______ the two cities. ________ the river is a bridge.
A．in; In
B．between; Over
C．between; On
D．outside; Under
