At that time, my little brother was about four years old and he missed mum all the time.

那时，我的小弟弟大约四岁，他一直想念妈妈。

youdao

When I was about four years old I had traveled by train.

大约在我四岁多的时候，我坐过火车。

youdao

They live to be about four years old, with both males and females dying soon after breeding.

它们的寿命约为4年，雌性和雄性都会在产卵后不久死去。

youdao

When she was about four years old, she heard her mother struggling to play a piece of music on the piano.

VOA: special.2010.04.09

He says the Leiopathes corals were shown to be about four thousand two hundred sixty-five years old.

VOA: special.2009.05.12

And they were in a room and there was a picture of me -- and this young couple had this cute kid, about four years old, named Sammy.

WHITEHOUSE: The White House

Kennedy, nearly 50 years ago. (Applause.) Now, at the time, I was about four months old -- (laughter) -- so my memory of this visit is a little hazy.

WHITEHOUSE: President Obama Arrives in Puerto Rico