16.They collected some valuable stamps___ they stayed in Shanghai
问题描述：
16.They collected some valuable stamps___ they stayed in Shanghai
A.while B.as C.since D.during
麻烦帮看一下,B项为什么不正确,帮分析一下,
17.I didn't manage to do it______ you had explained how
A.until B.unless C.when D.before
答
第一题应该选A,
As 翻译是：就像,好比..和题意不符.
第二题可以选B或者D,题出的有漏洞.你可以去问出题的人.
意思是,如果你不解释怎样做的话,我之前就没有计划去做.