A:①②
B:②③④
C:①③④
D:①②③④
用人的胰岛素基因制成的DNA探针检测下列物质,不能形成杂交分子的是( )
从东西半球和南北半球看,我国位于( )
—What can I do for you, sir?
—I'd like to see the manager of sales department.