患丙种球蛋白低下血症时最易感染下列哪类病原体
A.细菌
B.病毒
C.真菌
D.原虫
E.以上均易感
参考答案:A
about this computer program, a huge amount of time and energy .
A.Should I know; be saved
B.If I had known; can be saved
C.Had I known; would have been saved
D.Did I know; was saved
小明将塑料尺在衣服上摩擦几下,然后把尺靠近碎纸屑,纸屑被吸起,这种现象叫做_______ 。如果知道图中所示A球带正电,由现象可知,B球一定带________ 电