A single layer of cube-like cells that carry out active transport, facilitated diffusion, or secretion. They are found in mitochondria and kidneys. They often have cilia and microvilli on the surface.
credit definition The ability to obtain goods, money, or services in return for a promise to pay at some later date. The New Dictionary of Cultural Literacy, Third Edition
Letter of credit. A letter of credit is a document issued by a financial institution, or a similar party, assuring payment to a seller of goods and/or services provided certain documents have been presented to the bank.