海拔多在500米以上,表面平坦一般边缘有巨大陡坡的地形是( )
A.盆地
B.山地
C.高原
D.丘陵
答案:C
I don’t know ____ everyone in my class thinks I’m funny.
A.why is it that
B.why it is that
C.who is it which
D.who it is that
我国铁路标准轨距是()。