Because current federal law already forbids the use of federal funds to create embryos ( the earliest stage of human offspring before birth ) for research or to knowingly endanger an embryo ' s life , nbacxwill remain silwnt on embryo research 因为现行的联邦法律已经禁止使用联邦基金克隆研究用的? 933392死嘧哟?錾?暗淖钤缃锥危蛴幸馐兜匚芭咛纳? ? ? bac在胚胎研究这一问题上保持沉默。