—Haven't seen you for ages! Do you still work in Xi'an?
—________. It's four years since I worked there.
A:No, I don't.
B:No, I haven't.
C:Yes, I do.
D:Yes, I have
在“观察DNA和RNA的细胞中的分布”试验中,加入8%盐酸的目的不包括( )
关于如图所示国家的叙述,正确的是( )