五倍子鞣质从结构上看属于()
A.可水解鞣质低聚体
B.咖啡鞣质
C.逆没食子鞣质
D.缩合鞣质
E.没食子鞣质
参考答案:E
--- is the school from your home, do you know?
--- About 30 minutes’ walk.
A.How far
B.How long
C.How much
D.How soon
如图所示的四选项中,能正确表示光从空气进入水的是:[ ]
A.
B.
C.
D.