题型:选择题 — Why didn't you help the little boy?. — Oh, sorry. He had struggle to his feet ______ I ran over. [ ]A. before B. after C. until D. since 查看答案
题型:单项选择题 先天性巨结肠的常见X线征象是()A.近端结肠扩张而远端无狭窄段B.近端结肠狭窄,远端结肠扩张,并伴有功能障碍C.远端结肠狭窄,近端结肠扩张,并伴有功能障碍D.结肠病变区无钡剂潴留现象E.结肠仅有功能障碍 查看答案