A:1,3﹣二甲基戊烷
B:2﹣甲基﹣3﹣乙基丁烷
C:3,4﹣二甲基戊烷
D:2,3﹣二甲基戊烷
Generally speaking, when taken according to the directions, the drug has no side ____ .(效果,作用)