(在单偏光镜下,提升镜筒或下降物台,贝克线向矿物方向移动,矿物的表面光滑,边缘不清楚,该矿物的突起为()。
A、正高突起
B、低正突起
C、负突起
D、正极高突起
参考答案:B
对急性肾小球肾炎描述正确的是
A.是细菌引起的感染性疾病
B.病变主要累及肾小管
C.血尿、水肿、高血压是主要症状
D.常见的致病菌是葡萄球菌
E.多见于学龄前儿童
The issue of shortening the school time to four days and a half every week _____ at the meeting. [ ]
A. came up
B. came out
C. came to
D. came at