问题
Some of my friends are interested in science,but none of them can tell_____.
A:when UFOs will appear next time.
B:why do horses know the way.
C:where was this kind of plant foun
D:how do elephants communicate. ;
B:why do horses know the way.
C:where was this kind of plant foun
D:how do elephants communicate. ;
正确答案是：
