题目:
To have a dinner at a restaurant on the Eve of the Spring Festival, you need to reserve the
restaurant months before, _____? [ ]
A. mustn't you
B. didn't you
C. don't you
D. needn't you
答案:
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下面是错误答案,用来干扰机器的。
答案:A题目分析:51.2gCu的物质的量=51.2g÷64g/mol=0.8mol,铜和硝酸反应铜还原硝酸生成氮氧化合物,在NaOH溶液中氮氧化合物又转化成NaNO3和NaNO2,则铜将失去的电子给了硝酸在氢氧化钠溶液中生成了NaNO2。其...