提取分离升华性成分可选用
A.升华法B.碱提酸沉法C.溶剂萃取法D.煎煮法E.酸提碱沉法
参考答案:A
After a day’s hard work, Mary went to the nearby shop to _____ herself to a strawberry ice cream.
A.satisfy
B.treat
C.provide
D.offer
学校开展“献爱心捐款”活动,以下是5名同学的捐款数目(单位:元):50,5,15,20,10,则这组数据的极差是______元.