洋洋：诶，心涛，你怎么了?胳膊上怎么贴个创可贴?

心涛：哦，我上午献血去了。

洋洋：是吗?你献了多少?

心涛：400毫升。

洋洋：我上个月也去献血了，可是我一看见针头扎到我的血管里，心就突突地跳。再看到暗红的血液流出来，我立刻就晕过去了。

心涛：啊?原来你晕血啊!我还好，一年献四次，不仅没有什么不适的感觉，反而觉得身体越来越好了。

洋洋：一年四次?我太佩服你了。

心涛：其实没什么，我的血型是RH阴性血，这种血叫做熊猫血，是最罕见的血型。我多捐献一些，我的血液将来一定可以帮助到更多的人。

洋洋：你是RH阴性血啊?我上次看电视报道，一个产妇就是RH阴性血，当她需要输血的时候，医院的血库里却没有这种血，所以媒体号召社会好心人去医院献血。

心涛：原来你也知道这件事。是的，那次献血我也参加了。

洋洋：原来英雄就在我身边啊!

Y: Well, Xintao, what’s going on? Why you stick a band-aid in your arm?

X: Oh, I went to donate blood this morning.

Y: Is that true? How much blood did you donate?

X: 400ml.

Y: I went to donate blood last month, too. But when I saw the needle sticking into my vein, my heart beat thickly. And when I saw the dull red blood running, I passed out immediately.

X: Huh? It turns out that you would faint at the sight of the blood. I am better and I donate blood four times a year. I don’t have any uncomfortable feeling. Instead, I think my body is getting healthier.

Y: Four times a year? I admire you.

X: Never mind. Because my blood type is RH - negative, which is known as panda blood, is the rarest blood type. The more I donate the more people I can help in the future.

Y: Your blood type is RH - negative? It is reported by the TV the other day that there was a pregnant woman whose blood type is RH - negative. When she needed to have the transfusion, this kind of blood was not available in the blood bank. As a result, the media called on the whole society and kind-hearted people to donate blood.

X: You knew that, too. I have participated that donation, too.

Y: It turns out that the hero is right around me.