我国科学家研制出一种催化剂，能在室温下高效催化空气中甲醛的氧化，其反应如下：
HCHO+O2
CO2+H2O。下列有关说法正确的是
| A．该反应为吸热反应 | B．CO2分子由极性键形成的极性分子 |
| C．HCHO分子中有3个σ键，1个π键 | D．每生成1.8gH2O消耗2.24L O2 |
相关试题
The children all turned ____ the famous actress as she entered the classroom. 
| A．looked at | B．to look at |
C．to looking at | D．look at |
Edward, you play so well. But I ______ you played the piano. 
| A．didn’t know | B．hadn’t known |
C．don’t know | D．haven’t known |
She brought with her three friends, none of ______ I had ever met before. 
| A．them | B．who | C．whom | D．these |
I tried phoning her office, but I couldn’t _______. 
| A．get along | B．get on | C．get to | D．get through |
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