A:of which
B:from which
C:to which
D:about which
下列有关反射与反射弧关系的叙述中,正确的是( )
A~E为初中化学常见物质,他们之间有如图所示的转化和反应关系 (“→”表示某一种物质经一步反应可转化为另一种物质,“一”表示相连两种物质能发生化学反应,部分反应物、生成物及反应条件已略去).
We go to school from Monday to Friday. We have four classes in the____and three in the afternoon. We have____things to do after class. On Monday and____afternoon we have P.E. On Wednesday morning some of us have a singing class. On____morning some have a drawing class. On Friday____we practice speaking English.