题目内容:
Accordingtotheauthor,conventionalcropbreedinghas
A.beenforalongtimeexposedtoradiation. B.provedmuchsaferthanGMcropbreeding.
C.neverbeenmessedaroundwithgeneticmaterial.
D.producednoilleffectsonpeoplesofar.
参考答案:
答案解析: