Brick won't work, if you're going to build a wall, you have to plaster it on the outside, otherwise after ten or twenty years those bricks will loosen.,Qing bricks cost one copper coin each, and red bricks cost one copper coin each.,The old man said, "It depends on how many houses you want to build. Six houses would cost about 40,000, three houses around 20,000. How many houses are you planning to build"。