问题
选择题
— I the Great Wall next week.
— Have a good trip! [ ]
A. visit
B. visited
C. am visiting
D. have visited
答案
答案：C
搜题请搜索小程序“爱下问搜题”
— I the Great Wall next week.
— Have a good trip! [ ]
A. visit
B. visited
C. am visiting
D. have visited
答案：C
上位于x从0到1的一段弧长是（）。
