题干
—What do you think of China's four great works?
—I have heard of them before, but I've read ________ of them.
—I have heard of them before, but I've read ________ of them.
A：both
B：none
C：neither
D：all
答案(点此获取答案解析）
B
数之比为1:3时，正好完全发生氧化还原反应，X在还原产物中的化合价为( )