采用相同体积的有机溶剂,下列方法中,萃取效果较好的是A.1次萃取效果好 B.分多次 发布时间:2017-06-23 09:37 │ 来源:www.tikuol.com 题型:单项选择题 问题: 采用相同体积的有机溶剂,下列方法中,萃取效果较好的是A.1次萃取效果好 B.分多次萃取效果好 C.1次萃取与多次萃取效果相同 D.分4次萃取效果好 E.分3次萃取效果好
题型:单项选择题 At the party, Eric oughtn't to _____ the joke. Didn't you see the principal was a bit _____? [ ]A. be telling; embarrassing B. tell;embarrassed C. have told; embarrassing D. have told; embarrassed 查看答案