treasury bond　

treasury bond　国库债券，长期国库券，库存债券　

A negotiable，coupon-bearing debt obligation issued by the U.S.government and backed by its full faith and credit，having a maturity of more than 7years.Interest is paid semi-annually.Treasury bonds are exempt from state and local taxes.These securities have the longest maturity of any bond issued by the U.S.Treasury from 10to 30years.