你每30年就得把所有东西提高30厘米左右，那么为什么不建造一座可以漂浮的房子来简化这项工作呢？

You would have to raise everything about 30 centimeters once every 30 years, so why not make the job easier by making houses that can float.

youdao

排骨洗净后，切成5厘米左右小段。

Rinse the pork spareribs and cut into 5cm pieces.

youdao

我们假设半径是…，10到15厘米左右。

If we assume that the radius is... maybe it's 10, 15 centimeters.

youdao