机构客户办理（）万元以上记账式国债业务时，须严格实行换人复核。
A.20
B.30
C.50
D.100
参考答案：C
—According to my grandma,it is a good idea to eat chicken soup when you have a cold.
—________, scientists agree with her.[ ]
A. Sooner or later
B. Once in a while
C. To be exact
D. Believe it or not
有一个颊沟的牙是
A．上颌第一前磨牙B．上颌第二前磨牙C．上颌第一磨牙D．下颌第一磨牙E．下颌第一前磨牙
