大体积混凝土的浇筑温度不宜超过( )。
A. 20℃
B. 24℃
C. 28℃
D. 32℃
下列混凝土中养护时间不得低于14d的是( )。
A. 矿渣水泥拌制的混凝土
B. 有抗渗要求的混凝土
C. 环境水对混凝土有侵蚀作用时
D. 掺有速凝剂的混凝土
Not all fast-food chains are like McDonalds, KFC and Burger king.Fast food chains are not all ___1____ .
There are as many food choices in America as there are ____1______ in the _____2______.