Question

【题目】The game is not very difficult _______ you understand the rules.

A. until B. though

C. once D. unless

Answer 1

【答案】C

【解析】

考查条件状语从句。A. until直到---为止；B. though尽管；C. once一旦；D. unless除非。句意：一旦你明白了规则，这个游戏就不难了。此处是once“一旦”引导的条件状语从句，故选C。