确定病毒有无包膜的试验为（）
A.血凝血抑试验
B.中和试验
C.乙醚耐受试验
D.核酸酶试验
E.包涵体产生试验
参考答案：C
When it______the writer’s pastime, I was reminded______of the writer’s love of the sea.
A．came to; once more
B．talked to; once more
C．refers to; again and again
D．took up; once again
简述血清与血浆的主要区别？
