A:RNA聚合酶结合位点和限制性内切酶
B:染色体和细菌的质粒
C:细菌的质粒和固氮基因
D:tRNA和抗虫基因
Mr. Green didn't post the letter _________. He asked his son to do it for him.
下列有关名著内容的表述,不正确的两项是( )