电解1mol·L-1FeSO4和1mol·L-1ZnSO4的混合溶液,用石墨作电极,在阳极的产物是()。
A.H2
B.O2
C.SO2
D.OH-
参考答案:B
He doesn't read the English text very often. ______ he has failed again. [ ]
A. It is why
B. That's because
C. It is reason
D. That's why
功率控制的作用()
A.降低发射机的功率消耗
B.对抗衰落对信号的影响
C.降低网络中小区间的干扰
D.减少同小区内来自其它用户的干扰