题干
—Have you ___been to our town before?
—No, it is the first time that I___ here.
A：even; come
B：even; have come
C：ever; come
D：ever; have come
答案(点此获取答案解析）
D
代表碳原子， 
代表氢原子)。下列说法正确的是（ ）
