龋最好发于
A．上颌第一磨牙
B．上颌第二磨牙
C．下颌第一磨牙
D．下颌第二磨牙
E．上颌第一磨牙
参考答案：C
The poor ________ living in the mountain ________ top is covered with green trees.
A．are; which
B．are; of which
C．is; whose
D．are; whose
创建分组统计查询时，总计项应选择 【7】 。
