A:图①中向鸡血细胞液内加入少许嫩肉粉(含蛋白酶)有助于去除杂质
B:图②操作的目的是纯化DNA,去除溶于95%酒精中的杂质
C:图③中2 mol/L NaCl溶液能溶解黏稠物中的DNA
D:图④中向含DNA的NaCl溶液中加蒸馏水的目的是漂洗DNA
I get up at 6:30 in the morning. Then I wash my face and brush my teeth. I go to school at 7:00. I go to school by bike. Classes begin at 7:30. We have six lessons every day. We have three lessons in the morning and three in the afternoon. Classes are over at 5:00. I get home at 5:15. We have dinner at 6:00. I go to bed at 9:00.
如图,AB是⊙O的直径,CD为弦,CD⊥AB于E,则下列结论中不成立的是( )