《工伤保险条例》规定，( )应当按时缴纳工伤保险费。A．用人单位B．职工个人C．用人

焊锡过程中的假焊有以下哪些现象（）。

A.锡点未完全埋入焊点中

B.焊锡表面未完全浸锡

C.表面有锦孔

D.焊接时送锡量过多

老年妇女骨质疏松症的预防，下列哪项错误（）

A.提高骨峰值

B.注意钙的补充

C.重视对低骨量人群的预防

D.体育锻炼

E.禁酗酒，适当饮浓茶、咖啡等

测定NK细胞杀伤活性( )

A．Western Bloting
B．细胞毒实验
C．溶血空斑实验
D．E花环实验
E．PHA淋巴细胞转化实验

Man: I was expecting another hot, muggy day. Woman: But the wind has cooled things off, hasn't it Question: What does the woman mean

A．It's uncomfortable because of the wind.

B．It isn't as hot as the man thought.

C．The man expected it to be windy.

D．The wind hasn't made it any cooler.

下面哪个属于常见的履带板形式？（）

A.单齿形

B.雪地行

C.多齿形

D.岩石行