一旦到了那儿，他们就用卷尺，测径规和一种手持式激光器来测量一片500平方米地块内的所有树木的高度和干围。

Once there, they use tape measures, callipers and a hand-held laser to measure the heights and girths of all the trees within a 500-square-metre plot.

youdao

一旦到了那儿，他们就用卷尺，测径规和一种手持式激光器来测量一片500平方米地块内的所有树木的高度和干围。

Once there, they use tape measures, callipers and a hand-held laser to measure the heights and girths of all the trees within a 500-square-metre plot.

youdao