混凝土配合比设计的三大参数是()、()和()。
参考答案:水灰比;砂率;单位用水量
—When was the 29th Olympic Games held?
—________ 8:00 of August 8th, 2008, Beijing. [ ]
A. At
B. On
C. In
D. For
膳食纤维的生理功能。