A:亚洲、欧洲
B:北美洲、南美洲
C:欧洲、非洲
D:非洲、大洋洲
下列说法正确的是( )
设四面体的六条棱的长分别为1,1,1,1,2和a,且长为a的棱与长为2的棱异面,则a的取值范围是( )
-- It is reported that many wild animals in the world are _______ because of human behavior.
-- We must do something to stop people from hunting and selling these animals.