无铰链区的免疫球蛋白是（）
A.IgG、IgD
B.IgA、IgG
C.IgG、IgE
D.IgM、IgE
E.IgM、IgD
参考答案：D
____ your performance in physics ____ Jack's and you'll realize you should work harder. [ ]
A. Compare, with
B. Compared, to
C. Comparing, with
D. Comparing,to
