third backcross generation第三: third回交: rotation cross; backcross子代: offspring; filial generation回交子代: backcross progeny第二回交子代: second backcross generation下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:第三回交子代，即可在微信中查询翻译
