—How about the book you are reading?—Good indeed. It many problems we have come across in our study.
A:says
B:talks
C:reports
D:covers
如图,D是等边△ABC边AB上的一点,且AD:DB=1:2,现将△ABC折叠,使点C与D重合,折痕为EF,点E,F分别在AC和BC上,则CE:CF=( )
大象行走、袋鼠跳跃、鸵鸟奔跑,这些运动方式有利于动物
若函数f(x)=x+ 4x ,则不等式4≤f(x)<5的解集为____.