治疗风邪初中经络,应首选
A.防风通圣散B.地黄饮子C.补阳还五汤D.大秦艽汤
参考答案:D
在水溶液中,YO3n-和S2-发生如下反应:YO3n-+3S2-+6H+=Y-+3S↓+3H2O,则YO3n-中Y元素的化合价和原子最外层电子数分别为( )
A.+4、6
B.+7、7
C.+5、7
D.+5、5
Features of communicative activities in a CLT classroom usually involve information gap, choice of form and content, and ______.
A. presentation B. discussionC. conversation D. feedback