地球的平均半径是:( )
A:6371千米
B:40000千米
C:5460千米
D:7000千米
如图是植物进行光合作用的示意图,据图回答问题:
It is believed that travelling to Yangzhou in ________ March is ________ enjoyable experience.
Come on!It's 9 o'clock.