质量一定时，下列各组有机物不论按何种比例混合后完全燃烧，生成二氧化碳的质量不变的一组物质是 （ ）
| A．丙酸和甲酸乙酯 | B．甲醇和乙醇 | C．甲醇和乙酸 | D．乙醇和乙醚 |
相关试题
Progress______ so far very good and we are sure that the work will be finished on time.
| A．was | B．had been | C．has been | D．will be |
Charles was alone at home, with_______ looking after him.
| A．someone | B．anyone | C．not one | D．no one |
It is often ______ that human beings are naturally equipped to speak.
| A．said | B．to say | C．saying | D．being said |
I can’t leave. She told me that I ______ stay here until she comes back.
| A．can | B．must | C．will | D．may |
—— ______ , as a matter of fact
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