A:华华:西汉宦官蔡伦改进了造纸术
B:明明:东汉宦官蔡伦改进了造纸术
C:军军:西汉宦官蔡伦发明了造纸术
D:冬冬:东汉宦官蔡伦发明了造纸术
已知不重合的两直线l1与l2对应的斜率分别为k1与k2,则“k1=k2”是“l1∥l2”的( )
求函数y=cos2x+2sinx﹣2值域.
Swimming club
Do you like to swim? Do you want to swim well? Then we have good teachers to teach you. Opening time:2: 00 p.m ~ 9: 30 p.m
Ticket price: 15 yuan for children, 20 yuan for adults(成人)
Please call Mr. Wang at 877-778
Children dancing club
We are a dancing club for children of 5~14. we have lessons from 9:00 to 10: 30 every Saturday and Sunday.
If you like dancing, just join us.
Call Miss Wu at 263-566