晶体的面角是指（）。
A..晶面间的夹角
B.晶面法线间的夹角
C.晶棱间的夹角
参考答案：B
The Internet has become increasingly popular, ______ us to see as well as to hear all kinds of programmes.
A．to allow
B．allowing
C．allowed
D．having allowed
通过解决（）问题促进社会和谐发展。
A.人才流动
B.资源调配
C.失业问题
D.供求关系
