用适当的介、副词填空
In Britain，approximately every two out ________ three people own the houses they live in.
The loan is repaid monthly ________ a period of twenty years or more.
Most of the houses are equipped ________ central heating.
And the middleclass people，who make ________ about 40% of the total American population，live in detached houses or villas in the suburbs.
An American hopes and expects to exchange everything ________ something better.
The more money one has，the farther one lives ________ from the town centre.