位于地势的第二级阶梯，具有地势平坦，一望无际的高原是[ ]
A．青藏高原
B．内蒙古高原
C．黄土高原
D．云贵高原
答案：B
Daniel's grandmother is very old. She can't _____ him well.[ ]
A. listen
B. listen to
C. hear
D. hear to
铺底料的作用是什么？
