高级英语对话 第 330 课：血液检验-3

A: I came to this lab to have my blood drawn.
B: You are in the right place. Roll up your left sleeve and have a seat.
A: What am I being tested for?
B: Your doctor wants to know what your white blood cell count is.
A: What does my white blood cell count tell him?
B: Usually if your white count is off, the doctor suspects an infection.
A: How much will it hurt?
B: It is only a pin prick. I have to put this tourniquet on your arm to make the vein easier to find.
A: Is that my blood going into that tube?
B: That blood that just filled the tube is all that I needed. Thanks for coming in!