题干
I have many friends, ______ some are businessmen.
A：of them
B：from which
C：who of
D：of whom
答案(点此获取答案解析）
D
A：of them
B：from which
C：who of
D：of whom
与足量的稀硫酸混合加热使其水解，在所得乙醇分子中的氧原子含有的中子为
