Is that your pencil _____ the lost and found case? [ ]
A. in
B. at
C. on
D. of
答案:A
B细胞不表达下列哪一种CD分子
A.CD154(CD40
B.CDl9
C.CD40
D.CD79a与CD79b
E.CD80与CD86
下列电器设备中,主要利用电流热效应进行工作的是
A.话筒
B.电话
C.电视机
D.电饭锅