影响充型能力的主要因素是（）。
A.合金的流动性
B.浇注条件
C.铸型填充条件
D.以上均是
参考答案：D
Not until I began to work _____ how much time I had wasted. [ ]
A. didn't realize
B. did I realize
C. I didn't realize
D. I realized
A．E=，m=0
B．E=，m=
C．E=，m=0
D．E=，m=
，m=0
，m=
，m=0
，m=