a开头的名词

例句：

His aim was to become president.

他的目的`是当总统。

We aim to help the poorest families.

我们的目标是接济最贫困的家庭。

Draughts help to circulate air.

通风有助于循环空气。

Loud screams rent the air.

高声的尖叫划破了天空。

His hands clawed the air.

他的双手在空中乱抓。