柱子采用浇筑细石混凝土的方法最后固定，一般要分两次进行，第二次浇筑细石混凝土，应待第一次混凝土强度达到（）后，再浇筑满混凝土。

A．20%

B．25%

C．30%

D．35%

Both his parents died in a traffic accident when he was a baby, so he was ______by his grandma.[ ]

A. brought about      

B. brought up  

C. brought in        

D. brought down