对长度，宽度，高度，重量，面积等提问，可以用how， 也可以用what, 但how是对形容词提问，而what是对名词提问；如：
这个石头有多重？
How heavy is the stone? What is the weight of the stone?
这个建筑物有多高？
How tall is the building？ What is the height of the building?
这条河有多长？
How long is the river? What is the length of the river?
这条河有多深？
How deep is the river? What is the depth of the river?