A-A+
________you understand this rule you'll have
问题详情
________you understand this rule, you"ll have no further difficulty.
[A]Once
[B]Unless
[C]Only
[D]Until请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：A
27.A【解析】本题考查连词的用法。once意为“一旦…”；unless意为“如果不；除非”；only意为“只有”；until意为“直到…才…”。
