A:CH2Cl﹣CH2Cl 二氯乙烷
B: 1﹣甲基﹣1﹣丙醇
C: 1,4﹣二甲基丁烷
D: 2﹣乙基﹣1﹣丁烯
There are some____on the desk.Let's draw some pictures with them.
请回答: