[单项选择]The purpose of the research conducted 15 years ago was to ______.
A. find out the age groups of the TV audience B. assess some famous TV shows C. study the effects of violent TV shows on children D. evaluate the relationship between TV shows and crimes
第9题: [单项选择]可同时被酸和碱水解的是() A. 酯苷 B. 醇苷 C. C-苷 D. S-苷 E. N-苷 参考答案:A 答案解析:1.芥子酶可以水解芥子苷,芥子苷属于S-苷。 2.由于一般的苷键属缩醛结构,对稀碱较稳定,多数采用酸催化水解或酶水解。但酯苷、酚苷、烯醇苷和B位吸电子基团的苷类易为碱催化水解。