1.The plane finally arrived on the airport _________(safe)
问题描述：
1.The plane finally arrived on the airport _________(safe)
这道题为什么不能用safely 要用safety?
2.The ice on the river is not thick enough for us to skate on.(保持原意)
The ice on the river is ________ _________ for us to skate on.
这题为什么不能用thin enough ,而要用too thin?
答
1.safely 是副词,用来修饰动词arrive；而safety是名词,不能修饰动词.
2.too...to是固定搭配 这里是too thin to skate on,意思是“冰面太薄了以至于我们不能在上面滑冰”.