It'll have to make three trips back and forth for the three trees.

那样就需要为了这三棵树而往返三次。

youdao

What did you learn from the three trees?

你从这三棵树身上学到了什么？

youdao

Research has shown that just three rows of trees near poultry houses can reduce the release of dust and ammonia.

VOA: special.2009.09.08

Scientists at the agroforestry center say the use of fertilizer trees can reduce the need for chemical nitrogen by up to three-fourths.

VOA: special.2009.09.01

They measured the rings,or circles, inside thousands of ancient trees in more than three hundred places.

VOA: special.2010.05.25

Nava was in the habit of sitting with the girls on the back porch, overlooking the lemon trees, the three of them talking in low voices.

NEWYORKER: Waiting

Of the three types of coniferous trees studied, pines were found to be dying at the fastest rate.

CNN: Global warming threatens forests, study says

Yet the painter is skillful in depicting their clothing, and three trees that form the central axis in both works have a majesty that makes you wish they were not so incidental to the composition.

WSJ: Johan Zoffany | Yale Center for British Art | On the Strenth of His Portraits | By Tom L. Freudenheim