Among the most complex cryslals are that of silicon dioxide, which has seven different structures at varjous temperatures and pressures, the most common being quartz.

哪位高手分析下这个句子啊？尤其对前半句......那个that 怎改？

我觉得应该改为those，因为cryslals是复数。

among开头为倒装句，译为在。。。之中。