患者,男性,18岁,急腹症。腹部X线检查显示膈下有游离气体,提示腹腔内的病变是()
A.坏疽性
B.梗阻性
C.缺血性
D.穿孔性
E.绞窄性
参考答案:D
Nearly 90 percent of the young people in our country use the Internet, but about half of them use them every day. They visit chat rooms and sending e-mails. More and more scientists has begun to wonder: Is the Internet good or bad for kid? Some of them think what it is impossible to answer that question because the Internet has so much things. What’s more, recently studies show the online world can be helpful at some ways and dangerous as well. It can be both an educational resource and hiding place for bad people.
桃木具有纹理()、坚韧、不会()等优点。