溃疡型结肠炎最严重的并发症是()
A.结肠狭窄
B.结肠假息肉形成
C.瘘管形成
D.中毒性巨结肠
E.肛门直肠周围脓肿
参考答案:D
—I'm sorry I didn't make it to your party last night. —(). I know you're busy these days.
A. Of course
B. No kidding
C. That's all right
D. Don't mention it
实际值用A表示时()可表示为:△x=x-A。
A.相对误差
B.绝对误差
C.人身误差
D.基本误差