She lives at school .Soshe goes home__________Friday afternoon.[ ]
A.At
B.in
C.on
C.to
答案:C
什么是LKJ的允许速度?
在UV光谱中峰带Ⅰ很强为主峰,峰带Ⅱ较弱为次峰的化合物是( )
A.黄酮
B.异黄酮
C.查耳酮
D.黄酮醇
E.二氢黄酮