问题
单项选择题 A型题
普鲁卡因水溶液的不稳定性是因为下列哪种结构易被氧化()
A.酯键
B.苯胺基
C.二乙胺
D.N-乙基
E.苯基
答案
参考答案:B
普鲁卡因水溶液的不稳定性是因为下列哪种结构易被氧化()
A.酯键
B.苯胺基
C.二乙胺
D.N-乙基
E.苯基
参考答案:B
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1. How many days are there in this month? ______________________________________. 2. What day is the second day of this month? ______________________________________. 3. How many Mondays are there in this month? ______________________________________. 4. What day is the first day of the next (下一个) month? ______________________________________. 5. What date is the last Saturday in this month? ______________________________________. |