牙冠部近釉牙本质界，钙质球间未钙化的基质是（）
A.修复性牙本质
B.球间牙本质
C.髓周牙本质
D.托姆斯颗粒层
E.前期牙本质
参考答案：B
----------Do you know if Mr. Wu ______ to our school tomorrow?
----------I’ve no idea. If he ______, everyone ______ very happy.
A．will come; comes; will be
B．will come; will come; is
C．comes; will come; will be
D．comes; comes; will be
压缩机转子验收合格的标准是（）。
A、转子已进行动平衡实验
B、叶轮流道内无积垢、异物
C、叶片无缺损、裂纹
D、转子进行了全面的无损探伤检查
