Three officers and three of these assailants were killed.是什么意思？

Three officers and three of these assailants were killed.

有三名警察个三名袭击者丧生.

three

num. 三，三个，第三（章，页等）；n. 三岁，三个人[东西]，三，三个；adj. 三的，三个的；

例句
Outsiders who wed islanders are given only three years' right of abode at first.
岛外的人和岛民结婚之初只能获得三年的居住权。

officers

n. 军官( officer的名词复数 )，（政府，会社等的）高级官员[职员]，警察的头衔；

例句
The officers and crew prepared to abandon ship in an orderly fashion.
全体船员秩序井然地准备弃船。

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

these

adj. 这些的；pron. 这些；

例句
There's lots of money about these days for schemes like this.
近来这类计划资金充足。

assailants

n. 攻击者( assailant的名词复数 )；

例句
Three officers and three of these assailants were killed.
有三名警察个三名袭击者丧生.

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

killed

adj. 被杀死的，断开的；v. 杀死( kill的过去式和过去分词 )，使停止[结束，失败]，破坏，减弱，抵消，使痛苦，使受折磨；

例句
Six passengers were killed in the accident.
六名乘客在车祸中丧生。