胃肠道穿孔最常见的原因是()
A.腹腔脓肿
B.腹部外伤
C.十二指肠溃疡
D.胃肠道肿瘤
E.以上都不是
参考答案:C
解析:十二指肠溃疡是穿孔的常见原因。
I enjoyed the trip to Dalian Forest Zoo so much. I didn’t ___ want to go home.
A.hardly
B.regularly
C.possibly
D.really
流域和集水面积的概念。