题目

In our everyday lives we meet situations in which we take many things for granted（不去重视）.We only treasure things when they are gone.This is a sad truth of human nature.One day,I found myself as a witness to a similar situation. One evening,I left work and boarded the train.After entering,I noticed something unusual.The center of the car had a few empty seats while both ends were crowded with people standing.I didn't pay much attention and sat down on one of the empty seats.I sensed a funny smell.It wasn't long before I noticed a homeless person sleeping on three seats in fron金茶花是中国特有的观赏品种，但易得枯萎病．科学家在某种植物中找到了抗枯萎病的基因，通过如图所示的方法培育出了抗枯萎病的金茶花新品种．相关叙述正确的是（ ）A.图中①②在基因工程中依次叫做基因表达载体、目的基因B.形成③的操作中使用的酶有限制酶、DNA聚合酶和DNA连接酶C.由④培育至⑤过程中，体现了植物细胞的全能性D.在⑤幼苗中检测到抗枯萎病基因标志着成功培育新品种