问题
选择题
_____ you understand this rule, you will have no difficulty in finishing the task. [ ]
A. Until
B. Once
C. Though
D. Unless
答案
答案：B
搜题请搜索小程序“爱下问搜题”
_____ you understand this rule, you will have no difficulty in finishing the task. [ ]
A. Until
B. Once
C. Though
D. Unless
答案：B