题干
As Tim loves Shanghai a lot, he bought _______ one-way ticket to Shanghai.
A：an
B：a
C：/
答案(点此获取答案解析）
B
As Tim loves Shanghai a lot, he bought _______ one-way ticket to Shanghai.
A：an
B：a
C：/
，a个－CH3，其余为－OH，则羟基的个数为（ ）
