1.blood是不可数名词,没有复数形式,其本意为“血,血液”,也指无脊椎低等动物体中相当于血液的体液; 还可引申为“血统,亲属”“血气,脾气”。表示“流血”一般不说bleed blood,但在美国黑人英语中可说bleed black blood。
2.在new blood, fresh blood, old blood几个短语中blood统指“人员”。

be in the blood
家族共有的特征 be a quality with which many members of the same family are born
Acting runs in their blood; they have been actors for more than 150 years.演戏是他们家族遗传的天性,过去150年一直都有人当演员。
Most of my family are musicians, it is in the blood.我家里的人大都擅长音乐,是世传的。

in cold blood
冷静地,残酷地 sober, calm; unfeeling, hard-hearted
Let's think it over in cold blood.让我们冷静地考虑一下这个问题。
Millions of slaves were killed in cold blood.成千上万的奴隶被残酷地杀害了。

Blood is thicker than water.血浓于水。
Blood circulates through the body.血液在人体内循环。
The knife blade was stained with blood.刀上染有血迹。
The doctors analyzed the blood sample for anemia.医生们分析了贫血的血样。
The doctor wanted a specimen of his blood.医生要他的血样。
Blood donors give blood for use in hospitals.献血者献血供医院使用。
The mayor launched an appeal to the public to give blood to the victims of the disaster.市长向公众呼吁为灾难受害者献血。
Blood was still oozing from the wound.伤口仍在流血。
Blood trickled down his face.血从他脸上一滴滴流下来。
Much blood was shed in the war.很多人在战争中流血牺牲。
Their money bleeds black blood.他们的钱沾满了黑人的血。
That's blood and guilt money.那是杀人犯罪的血腥钱。
The war cost so much British blood.英国人在这场战争中伤亡惨重。
He didn't act like a blood all the time.他的行动总是缺乏刚强之气。
He is of the purest Arab blood.他是纯阿拉伯血统。
They have Jewish blood.他们有犹太血统。
The boy had the blood in him and there it was.这孩子脾气不好,那就是证明。
That would put blood in the eye of his critics.那会使得批评他的人更加恼火。
It makes my blood boil.它使我大怒。
Men will say things when their blood is up which they regret after they have cooled down.人们发怒时会说一些过头的话,当他们冷静下来又感到后悔。
His blood was up.他情绪激昂。

［同义词］   ancestry, bloodshed, gore, heritage, lineage, murder, slaughter
［词源］  ＜古英语blod(血)