【单选题】1,3- 环己二烯和 1,4- 环己二烯中哪一个在 200nm 以上有紫外吸收?
【多选题】Mesopotamian culture were brought by________
【单选题】溴代环己烷, 5- 溴 -1,3- 环己二烯, 3- 溴环己烯脱卤化氢的难到易的顺序()
A.
5-溴-1,3-环己二烯 > 3-溴环己烯 > 溴代环己烷
B.
3-溴环己烯 > 溴代环己烷> 5-溴-1,3-环己二烯
C.
溴代环己烷> 5-溴-1,3-环己二烯 > 3-溴环己烯
D.
3-溴环己烯 >5-溴-1,3-环己二烯 > 溴代环己烷
【判断题】Mesopotamian culture was among the earliest civilizations. The wheel, units of weights and measures, and writing all originated in Mesopotamia.
【判断题】当植物细胞内的NADPH过多时,不会对戊糖磷酸途径起反馈抑制作用。
【单选题】利息备付率表示项目的利润偿付利息的保证倍数。对于正常运营的企业,利息备付率应大于( )。
【判断题】Mesopotamian culture was among the earliest civilizations. The wheel, units of weight and measures, and writing all originated in Mesopotamia.