题目

下列有机物的命名正确的是 A．1,2─二甲基戊烷    B．2─乙基戊烷   C．3,4─二甲基戊烷     D．3─甲基己烷 答案：DMy parents are ________ to live in the countryside,where the air is clean and the vegetables are fresh．A．properB．satisfyingC．contentD．disappointed