【单选题】水溶液中胺的碱性强弱是多种因素共同作用的结果各类胺的碱性由强到弱大致如下顺序
A.
脂肪仲胺、脂肪伯胺、芳香伯胺、芳香仲胺、芳香叔胺
B.
脂肪伯胺、脂肪仲胺、芳香伯胺、芳香仲胺、芳香叔胺
C.
芳香伯胺、芳香仲胺、芳香叔胺、脂肪仲胺、脂肪伯胺
D.
芳香伯胺、芳香仲胺、芳香叔胺、脂肪伯胺、脂肪仲胺
【判断题】The year 1997 saw the launch of Project 211, with the aim to establish 211 key institutions of higher education. Project 985, which was launched in 1998 with the aim of building world-class universiti...
【单选题】下列哪种农药以中枢性肌肉松弛剂为解毒剂( )。
【单选题】女,22岁,初产妇。妊娠38周,规律宫缩7小时。检查:宫口开大5cm,S=0,枕左前位,胎心148次/分,预估胎儿体重2800g。目前应采取的处理是
【单选题】---We’ve seen many more days of blue skies recently. ---True. But back in 1998, ________ Beijing started its “Defending the Blue Sky” program, the city only ________ about 100 days a year.