--__________ you __________ in this school for more than ten years?
--Yes, I __________ here in 2002.
A:Did; come, came
B:Have; been; came
C:Did; come; have been
D:Have; come; came
从A出发,发生图示中的一系列反应,其中B和C按1:2反应生成Z,F和E按1:2反应生成W,W和Z互为同分异构体.
回答下列问题:
对下列各图所表示的生物学意义的描述,正确的是( )