What did he _____ at the meeting? [ ]
A. say
B. speak
C. talk
D. tell
答案:A
绘图题:背画带风扇磨煤机热风干燥的直吹式制粉系统图,标出主要设备的名称。
急性链球菌感染肾炎补体C3及总补体恢复的时间是( )
A.1周以内
B.2周以内
C.以上均非
D.4周后8周以内
E.3周以内