下列命题中,逆命题不正确的是[ ]
A.两直线平行,同旁内角互补
B.对顶角相等
C.直角三角形的两个锐角互余
D.直角三角形两条直角边的平方和等于斜边的平方
答案:B
______ is well known to everyone, I should say, is that a man becomes learned by asking questions.
A.Who
B.It
C.As
D.What
下消化道内镜检查的并发症不包括
A.肠出血
B.肠穿孔
C.心脑血管意外
D.术后发热
E.肠系膜裂伤