题目

Choose the best answer. (根据短文内容，选择最恰当的答案) FromBen and Emma ToSamira, Daisuke, Peter, Marisol Subjectpenfriends Hi everybody, We saw your names on the Penfriends list. You all said you wanted to get e-mails from the English children. So here we are! We live near Oxford, in the south of England. We are 11 years old (Emma) and 10 years old (Ben). We go to school in Oxford. Our school has 400 boys and girls between 8 and 13. We have lessons from Monday to Saturday from 9:00 a.m. to, lunchtime. (School lunches are horrible! We don't like them.) After lunc下列关于醛的判断正确的是(　　)A.用溴水检验CH2=CH—CHO中是否含有碳碳双键B.1 mol HCHO发生银镜反应最多生成2 mol AgC.对甲基苯甲醛()使高锰酸钾酸性溶液褪色，说明它含有醛基D.能发生银镜反应的有机物不一定是醛类