He's a good teacher, but his inappropriate manner does tend ______ people.

A．to annoy

B．annoying

C．annoy

D．to annoying

下列哪种不是HLA复合体的遗传特征（）

A.多基因性

B.基因常需要重组

C.共显性遗传

D.单元型遗传

E.连锁不平衡