bimetallism

n [U] use of two metals, esp gold and silver, with a fixed ratio to each other as the monetary standard 复本位制（尤指金银二本位制, 在货币的法定纯度中保持二者的固定比率）.

bill of lading, bill of rights, bill of sale, billabong, billboard, billet, billet-doux, billfold, billhook, billiard-, billiards, billion, billow, billowy, billposter (also billsticker), billy, billy-goat, billy-oh (also billy-o), biltong, bimetallic, bimonthly, bin, binary, binary digit, binary notation system, binary star, bind, binder, bindery, binding, bindweed, bine, binge, bingo, binnacle, binoculars, binomial, biochemical, biochemist, biochemistry,