在黄土高原行走,本来距离很近,却常常要绕道远行,其原因是( )
A:冰川广布
B:沼泽遍布
C:千沟万壑
D:河道纵横
It's very important for students to develop good study____.
如图.在菱形ABCD中,对角线AC,BD交于点O,下列说法错误的是( )