答案：C

题目分析：考查状语从句连词的选用。解题的关键是正确把握两个分句的逻辑关系，同时熟悉每个连词的意义和用法。根据句意可知两分句是让步关系，as long as 只要，引导条件状语从句,可排除。When，while, as都可引导让步状语从句，其区别如下：when虽然/尽管，引导的让步状语从句一般放后面，如He walks when he might take a taxi ; while尽管，引导的让步状语从句一般放句首，如：While the Internet is of great help，I don’t think it’s a good idea to spend too much time on it; as 尽管，引导的让步状语从句要用倒装结构，如：Child as he is, he knows a lot.