转炉炼钢吹炼过程中铁矿石起到（）。
A.化渣剂
B.造渣剂
C.冷却剂
D.护炉剂
参考答案：A, C
. — I sent him the dictionary by mail this morning .
—You ____ that; he''s coming tomorrow afternoon .
A．needn''t have done
B．didn''t have to
C．needn''t do
D．mustn''t do
五脏共同的生理特点是
A．排泄水液
B．贮藏精气
C．传化水液
D．传化水谷
E．传导糟粕
