推理是一种重要的学习方法．下列推理中正确的是
| A．物质与氧气发生的反应都是氧化反应，则氧化反应一定要有氧气参加 |
| B．分子是保持物质化学性质的最小粒子，则保持物质化学性质的最小粒子一定是分子 |
| C．分子、原子都是不带电的微粒，但不带电的微粒不一定都是分子、原子 |
| D．催化剂能改变其它物质的化学反应速率，则能改变其它物质化学反应速率的物质都是催化剂 |
相关试题
--- Can you tell me ______ on the Internet? --- OK, mum.
| A． | how can I use QQ | B． | where can I use QQ |
| C． | how I can use QQ | D． | whether can I use QQ |
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 |
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