题干
Helen is a little in geography. She can't find that city on the map.
A：good
B：doing
C：weak
D：afraid
答案(点此获取答案解析）
C
Helen is a little in geography. She can't find that city on the map.
A：good
B：doing
C：weak
D：afraid
中，
，公比
1，若
，则