地下、半地下建筑(室)和一类高层建筑的耐火等级不低于()。
A.一级
B.二级
C.三级
D.四级
参考答案:A
解析:地下、半地下建筑(室)和一类高层建筑的耐火等级不低于一级。
All these gifts must be mailed immediately ________ in time for Christmas. [ ]
A. in order to have received
B. in order to receive
C. so as to be received
D. so as to be receiving
制定比赛阵型主要依据对方队的队员特点和打法。