小明同学从 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（）
| A． |
①②④⑤ |
| B． |
①②③ |
| C． |
④⑤ |
| D． |
①②③⑤ |
相关试题
Thousands of houses _______ by the floods in Guangxi last month.
| A． | destroy | B． | destroyed | C． | have destroyed | D． | were destroyed |
more, and you'll improve your spoken English.
| A． | Speak | B． | Speaks | C． | Speaking | D． | To speak |
--- I've just got a postcard from my pen friend.
--- Let me have a look
. Wow.nice card!
| A． | What | B． | What a | C． | How | D． | Why |
--- What is your favourite sport?
--- Swimming, I think. It's of all.
| A． | earsier | B． | more difficult | C． | the most interesting | D． | the most boring |
粤公网安备 44130202000953号