便秘的病因病机（）
A.饮食不节
B.情志失调
C.年老体衰
D.感受外邪
E.阴血亏少
参考答案：A, B, C, E
过期流产的特点有（）
A.可导致凝血功能障碍
B.早孕反应消失
C.子宫小于孕周
D.未闻胎心
E.妊娠试验（+）
Last Monday, I was asked to give the new students a test ______ their English level.[ ]
A. grading
B. to have graded
C. to grade
D. having graded
