A：东高西低
B：南高北低
C：西高东低
D：北高南低
如果a的平方是正数，那么a是( )
请根据对话选词填空
ducks quiet nature park people buildings
There is a____. The nature park is____. There aren't many ____. There aren't many tall____. There are some animals. They are____and rabbits.
下列各句划线的成语使用错误的一项是（ ）
针对一位多次去过西藏的朋友所提出的三条建议，请结合所学地理知识分别解释其原因。
