根据下列HBV感染状况检查结果,可作为献血员的是抗HBc抗HBe抗HBsHBsAgA.+--+
B.--+-
C.-+-+
D.---+
E.++--
参考答案:B
绝缘细线上端固定,下端悬挂一小球N,由绝缘支架支撑着一小球M,当M靠近N时,N偏离竖直方向,如图.下列关于M、N带电情况表述正确的是( )
A.M一定带正电
B.M、N都带正电
C.M、N都带负电
D.M、N带异种电荷
She volleyball regularly for many years when she was young.
A.was playing
B.played
C.has played
D.had played