在国外目前圆形风管的使用率都变得越来越普及，而国内的使用比例只有20%左右。

Now the utilization of circular duct becomes more and more popular abroad, but in China the utilization rate of circular duct is only about 20%.

youdao

在国外目前圆形风管的使用率都变得越来越普及，而国内的使用比例只有20%左右。

Now the utilization of circular duct becomes more and more popular abroad, but in China the utilization rate of circular duct is only about 20%.

youdao