they know how big and how far away it is

how far away is Silbury how far away is the post office?how many miles away is it?为什 how is big it "do you know how far is it from...to..." 请问：How Big Is the Sun?How Far Is It from Us 的答案是什么 how far is Tom away from school? How far away is Silbury?怎么回答? how far away is happiness from How far is it always how far is it form How far is it?________. Foever ,How far is it?