瓷贴面的特征不包括（）
A.恢复良好的牙体外形
B.去除牙体组织量少
C.完全遮盖基牙颜色
D.对牙龈健康较好
E.治疗费用易被接受
参考答案：C
Joe, my close friend, moved to Beijing years ago, and I him since then. [ ]
A. don't see
B. didn't see
C. haven't seen
D. won't see
电焊机（）及（）的保护必须完好。
