bítóu
битоу
би2 тоу2
http://www.chinese-russian.com/zd/ci/130912
bǐtóu
би3 тоу2
http://www.chinese-russian.com/zd/ci/112098
bìtóu
би4 тоу2
http://www.chinese-russian.com/zd/ci/7329