完形填空some are unpleasant to our ears __while____ others are very pleasant to hear.
问题描述：
完形填空some are unpleasant to our ears __while____ others are very pleasant to hear.
为什么用while,不用but
答
这里主要原因是因为和but 相比,while有“对比”的含义在里面,前者感到unpleasant,而后者恰恰相反,感到pleasant.
but是连词,连接两个句子时前面一般有逗号,但是,做题时要保证准确率就要依据语法及意思,实在不会时可以记一下前面的方法.