问题 选择题

下列说法不正确的是

A.常温下,氧气与所有金属都能反应

B.棉花属于天然有机高分子材料

C.结晶水合物属于纯净物

D.中和反应一定有盐和水生成  

答案

答案:A

A、常温下,氧气不与金等反应,故A说法不正确;

B、棉花属于天然有机高分子材料,故B说法正确;

C、结晶水合物属于纯净物,故C说法正确;

D、中和反应是指酸和碱反应生成盐和水的反应,故D说法正确。

完形填空
完形填空。
    You'll see a new doctor at a hospital near London if you go there. He's very clever,   1   he never speaks.
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