Swallows were darting through the clouds.是什么意思？

Swallows were darting through the clouds.

燕子穿云急飞.

swallows

n. （吃或喝的）一口( swallow的名词复数 )；

例句
There were swallows in the cloudless blue sky...
燕子在万里无云的蓝天飞翔。

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。

darting

v. 投掷，投射( dart的现在分词 )，向前冲，飞奔；

例句
Swallows were darting through the clouds.
燕子穿云急飞.

through

prep. 通过，穿过，经由，透过，凭借；adv. 从头到尾，彻底，自始至终；adj. （电话）接通，通话完毕，有洞的，直达的；

例句
The proposal was instantly voted through with two to one in favour, accompanied by enthusiastic applause...
在热烈的掌声中，提案以2比1的优势很快通过了表决。

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。

clouds

n. 云( cloud的名词复数 )，团，群，造成不愉快或不明朗的事物；

例句
The presence or absence of clouds can have an important impact on heat transfer...
有无云层对热量的传递会产生重要的影响。