涂膜防水层的平均厚度应符合设计要求，最小厚度不应小于设计厚度的80%。
参考答案：对
—I'm sorry I can't go to your party tonight.
—________? Haven't we agreed on it?[ ]
A. What is it
B. Why don't you
C. What do you think
D. How is it
血清与血浆的主要区别在于血清中不含
A．水
B．电解质
C．凝血因子Ⅰ
D．白蛋白
E．红细胞
