A:2个甲基,可能生成4种一氯代物
B:3个甲基,可能生成5种一氯代物
C:3个甲基,可能生成3种一氯代物
D:4个甲基,可能生成4种一氯代物
要点提示1)Where did you go over the summer holiday? 2)Who did you go with? 3)How did you go there? 4)What did you do there? 5)How did you feel?
我们生活在充满声音的海洋里,歌声、风声、汽车喇叭声…这些不同的声音具有不同的特性,在繁华闹市区设立的噪声检测器的牌子上有“62dB”字样 ,这是用来测定声音的( )