反胃的主要病因病理是（）
A.胃失和降
B.中焦虚寒
C.下焦火衰
D.肝气横逆
E.肺失肃降
参考答案：A, B, C
真核生物DNA复制中填补冈崎片段间空隙的酶是（）
A.poll
B.polα
C.polβ
D.polγ
E.polδ
The story is easy for us to read because there are _______ new words in it. [ ]
A. little
B. a little
C. few
D. a few
