Why do most pageants have a historical flavor
A. Because most pageants take place for celebration.
B. Many pageants take place for amusement.
C. A lot of pageants take place for religion.
D. Because pageants usually take place for competition.
共轭双键的π→π*跃迁吸收峰在
A. λmax<200nm(远紫外区)
B. 200nm左右
C. 200~400nm
D. λmax >210m
E. 100~500V
除去或减弱载体吸附力称为
A. 活化
B. 钝化
C. 活性高的薄板
D. 极性强的展开剂
E. 载体
范氏方程为H=A+Cu
A. 毛细管气相色谱法
B. 高效液相色谱法
C. TLC法
D. 电泳法
E. 纸色谱法