根据病因最常见的癫痫类型是（）
A.症状性癫痫
B.特发性癫痫
C.隐源性癫痫
D.妊娠性癫痫
E.经期性癫痫
参考答案：C
—Do you know ________ this time yesterday?
—Sorry, I don't know. [ ]
A. what she is doing
B. what was she doing
C. what she was doing
加气混凝土是以含钙材料、______和发泡剂为原料制成的。
