结肠一直肠息肉按其病理性质可分为（）
A.肿瘤性息肉
B.错构瘤性息肉
C.炎性息肉
D.增生性息肉
E.溃疡性息肉
参考答案：A, B, C, D
There ___________ a cat and two birds in the tree just now. [ ]
A. were
B. has
C. is
D. was
—Why don’t you go home now ?
—OK. Let’s go. [ ]
A.Why not
B.Would you like to
C.How about
D.What about
