问题
选择题
_______ you have been to America for many times, you must know something about this country. [ ]
A. Since
B. Although
C. Unless
D. When
答案
答案：A
搜题请搜索小程序“爱下问搜题”
_______ you have been to America for many times, you must know something about this country. [ ]
A. Since
B. Although
C. Unless
D. When
答案：A