age可數還是不可數

It's been an age since we've seen them.

我們有很長一段時間沒有見到他們了。

The car is in remarkably good condition for its age.

就車齡而論，這輛車的`狀況好極了。

She entered public life at the age of 25.

她25歲時開始了經常拋頭露面的工作。

The competition is open to young people under the age of 18.

這項比賽讓18歲以下的青少年參加。

By the age of 21 he controlled the company.

他21歲就掌管了公司。