The two countries signed an agreement to jointly launch satellites.是什么意思？

The two countries signed an agreement to jointly launch satellites.

两国曾签订了联合发射人造卫星的协议。

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

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

two

n. 两个，两个东西，两点钟，一对；adj. 两个的，我

例句
He has been absent from his desk for two weeks...
他已经有两个星期没有坐在办公桌前了。

countries

n. 国家( country的名词复数 )，国土，郊外，地区；

例句
The two countries signed an agreement to jointly launch satellites.
两国曾签订了联合发射人造卫星的协议。

signed

adj. 有符号的，有正负之分的；

例句
The two countries signed an agreement to jointly launch satellites.
两国曾签订了联合发射人造卫星的协议。

an

art. 一（在元音字母前代替不定代词a），一任一某一，一个；

例句
He started eating an apple...
他开始吃苹果。

agreement

n. 协定，协议，同意，一致，合同书，（词之间性、数、人称方面与…）一致；

例句
Reaching this agreement so quickly was a great achievement...
如此快速达成这项协定是一大伟绩。

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

jointly

adv. 共同地，联合地，连带地，旅；

例句
The two countries signed an agreement to jointly launch satellites.
两国曾签订了联合发射人造卫星的协议。

launch

vt. 发射，[计算机]开始（应用程序），发动，开展（活动、计划等）；vi. 投入，着手进行，热衷于…；n. 投掷，大船上的小艇，大型敞篷摩托艇；

例句
The two countries signed an agreement to jointly launch satellites.
两国曾签订了联合发射人造卫星的协议。

satellites

n. 卫星( satellite的名词复数 )，人造卫星，卫星国，附庸国；

例句
Weather satellites have observed a ring of volcanic ash girdling the earth...
气象卫星观测到一个环绕地球的火山灰带。