37. 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. B第一个小分句怎么还原到正常语序就是there are silicon dioxide among...这样的话那个of还怎么解释？还有这样的假设改法that——》there对吗？ besides，请解释下第三小分句，bow～ 我想主句还原应该是 cryslals of silicon dioxide are among the most complex cryslals 因为代词指代的东西都是向前找的 | 
