室内地面中,楼层地面的基本构造层次为( )。
A.隔热层
B.面层
C.垫层
D.基层(楼板)
E.保温层
参考答案:B,E
— The plane is due to take off at 7:50 from the airport. _____ we fail to arrive there in time?
— Try to take another flight then. [ ]
A. What if
B. As if
C. Even if
D. Only if
家庭漂白术使用的漂白剂是()
A.30%过氧化氢
B.10%~15%过氧化脲
C.15%过硼酸钠
D.10%~15%过氧化氢
E.30%过氧化脲