题目内容：
Now this tiny housing solution is ______________ in urban areas in the U.S., and Canada.选择一项：
A.
gain ground
B.
gain ground on
C.
gain ground upon
参考答案：
选择题：Now this tiny housing solution is ______________ i
- 题目分类：国家开放大学理工英语1
- 题目类型：选择题
- 查看权限：VIP
选择一项：
A.
gain ground
B.
gain ground on
C.
gain ground upon