HBV感染进入后期与传染减低的指标是:()
A.HBsAg(+)
B.抗-HBs(+)
C.HBeAg(+)
D.抗-HBc(+)
E.抗-Hbe(+)
参考答案:E
— What a nice MP5! Whose is it?
— It's . My father bought me last week. [ ]
A. me
B. him
C. his
D. mine
如图是研究电磁感应现象的装置.从正对纸面的角度看,图中导体a b______(选填“上下”、“左右”、“前后”)运动时,电流表指针会转动,根据这一现象,制成了______机,该现象是由______首先发现的.