口腔颌面部损伤时常见的窒息原因有（）
A.组织移位
B.组织肿胀
C.舌后坠
D.血凝块和分泌物堵塞气道
E.气管被压闭
参考答案：A, B, C, D
—May I come in? I'm sorry I'm late.
—Come in, please. But could you tell me ?[ ]
A. how do you come to school
B. what were you doing then
C. who you talked with
D. why you are late
某建筑工程建筑面积100000m2，现浇剪力墙结构。底板厚3m，底板混凝土强度等级C36/P12。底板钢筋施工时，板厚1.5m处的HRB335级直径16mm钢筋，后来用HPB235级直径10mm的钢筋进行代换。
钢筋实测抗拉强度与实测屈服强度之比不小于( )。
A．1.25
B．1.00
C．0.75
D．0.50
