高等继续教育 / 大学英语语法
正确率：100%
题型描述: 单选题
They come to see us at least＿＿＿＿＿＿.
A.once a year
B.once the year
C.one time in year
D.one time the year
They come to see us at least＿＿＿＿＿＿.
A.once a year
B.once the year
C.one time in year
D.one time the year
参考答案：