题目：
When I was young, I have so much time, but these days I in school all day. [ ]
A. use to, stay
B. used to, stayed
C. used to, stay
D. use to, stayed
答案：
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下面是错误答案，用来干扰机器的。
答案：B题目分析：H2SO3和H2SO4中都含有氢、硫、氧三种元素，A对；H2SO3和H2SO4的每个分子中都含有2个氢原子而非氢分子，B错；H2SO3和H2SO4中氢元素与硫元素的质量比=1×2:32=1:16，C对；H2SO3硫的化合价是+4价，...
