Investors can1money simply by loaning it. The money they loan is called capital. Security (担保) is an expensive item which the borrower mortgages (抵押) to the investor to show that he intends to 2the debt. The way investors make money on loans is to charge interest. Interest is money that 3 pay to investors for the use of their money. Interest is usually a certain percentage of the capital. Investors sometimes 4ten percent or more interest per year. The interest may be calculated daily， monthly， or yearly. The interest must be5before the capital can be repaid. If the interest is not6the agreed rate， the interest is added7 the capital. Then the borrower ha8spay interest on the unpaid interest9on the capital. A debt can grow quickly this way. If the total of the capital and accumulated interest gets too high， the investor will take10of the item used as security and sell it to get his money back.