Where did you go ____ vacation?[ ]
A. on
B. at
C. for
D. to
答案:A
“礼”是从()活动及其意识发端的
A、宗教
B、贸易
C、军事
D、外交
前牙反牙合骨骼Ⅰ型其诊断标准是
A.ANB角>5°
B.ANB角≥0°
C.ANB角<0°
D.ANB角<-5°
E.ANB角<2°