下列说法正确的是（ ）
A．棉、麻、羊毛及合成纤维完全燃烧都只生成CO2和H2O
B．蛋白质是结构复杂的高分子化合物，分子中都含有C、H、O、N四种元素
C．用KMnO4酸性溶液鉴别CH3CH＝CHCH2OH和CH3CH2CH2CHO
D．向盛有少量苯酚稀溶液试管中滴加少量稀溴水，边滴边振荡，有白色沉淀出现
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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