A:我国陆地面积达960平方千米
B:与我国陆地相邻的国家有14个
C:我国陆地界线长18000多千米
D:我国大陆海岸线长2万多千米
下列有关生物变异的叙述中,正确的是( )
在Rt△ABC中,∠ACB=90°,O在AB上,⊙经过点A,与CB切于D,分别交AB、AC于E、F.
(1)求证:sin∠B=CDBD;
(2)连CE,AD相交于P,sinB=25,求CPEP.
The old man keeps walking around this street. I think he is new here and now he has trouble ____ (find) his way.