Is this school ______you studied in three years ago?
A.where
B.that
C.the one
D.which
答案:C
关于浸膏剂和流浸膏剂的叙述正确的是( )
A.流浸膏剂和浸膏剂制备时所用的溶剂均为不同浓度的乙醇B.流浸膏剂的浓度为每1ml相当于原药材1g,而浸膏剂每1ml相当于原药材2~5gC.流浸膏剂与浸膏剂的成品均应测定含醇量D.除另有规定外,渗漉法制备流浸膏时应先收集药材量85%的初漉液另器保存E.浸膏剂的含水量约为5%
简述网络安全的概念