Which of the following is an example of a constraint

A．A predefined budge

B．The threat of a strike by a subcontracto

C．Relationship with the selle

D．The method used to measure project performanc

浅Ⅱ度烧伤创面特征是（）

A.局部红肿

B.局部水泡

C.红白相间

D.可见网状栓塞血管

E.焦黄无水泡