题干
—________?
—He is a teacher.
A：What does he look like?
B：How old is he?
C：What does he do?
D：Where is he?
答案(点此获取答案解析）
C
—________?
—He is a teacher.
A：What does he look like?
B：How old is he?
C：What does he do?
D：Where is he?
SO2中获得以下信息：①该反应反应物是硫和氧气；②反应发生条件是点燃；③反应前后元素种类和原子个数不变；④反应前后分子总数保持不变；⑤参加反应的硫和氧气的质量比为2：1．其中正确的信息是（ ）