Jack is only four years old.

杰克只有四岁。

youdao

Little Jack has learned to do lots of things on his own, though he is only four years old.

尽管小杰克只有四岁，但他已经学会了自己做很多事情。

youdao

Now it takes only four years.

而现在仅需4年。

youdao

History records say that in only four years the area around Dawson produced more than fifty-one million dollars in gold.

VOA: special.2009.02.11

And not only was it a party school, you were going to have an amazing time for the four years and beyond.

不仅是个派对大学，而且未来四年甚至以后，都会过得很快乐。

哈佛公开课 - 幸福课课程节选

Rutherford Hayes kept his promise to serve only four years.

VOA: special.2010.03.11

He would serve only four years of his six-year term, resigning to run for president in 2007.

CNN: Barack Obama

And despite being only four years old, the company has customers like Clorox, Target, Facebook and J.

FORBES: Apptio: Switzerland of the Tech Wars

The Rio Sol winery is only four years old, the result of a Brazilian-Portuguese venture called (unintelligible) Brazil.

NPR: Brazil Produces Award-Winning Wine