The dressing-table was bare, a pair of ivory hair brushes.
A. in addition to
B. except
C. except for
D. besides
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Five minutes earlier, they could have caught the last No. 127 bus.
A. but
B. so
C. and
D. or
三萜皂苷元由多少个碳原子组成
A. 27个
B. 30个
C. 25个
D. 28个
E. 21个
为了从水溶液中萃取皂苷类化合物，常选用的溶剂是
A. 乙醚
B. 石油醚
C. 丙酮
D. 正丁醇
E. 乙醇
甾体皂苷元具有
A. 六个环
B. 五个环
C. 四个环
D. 三个环
E. 二个环
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