乳牙期前牙反牙合,下颌前突的矫正年龄一般为
A.0~1岁
B.3~6岁
C.1~2岁
D.6岁以上
E.2~3岁
参考答案:C
So far the teachers have _____ several solutions to the problem that some students often fail to hand in their
homework on time. [ ]
A. worked out
B. made out
C. come out
D. burst out
由于钻井液侵入,储层在径向上可分为几个带?什么是高侵和低侵?