一型观测线测出的倒凹区主要位于基牙的()。
A.近缺隙侧
B.远缺隙侧
C.近远中均有明显倒凹
D.面
E.外形高点区
参考答案:B
Only _____ as an interpreter _____ how important it was to practise spoken English.
A.when did I work…I realized
B.when did I work…did I realize
C.when I work…did I realize
D.when I worked…did I realize
两股钢轨接头相错,其相错量不得大于3m。