他们用特殊的超细纤维来替代粗糙的砂石颗粒，以强化水泥。

They used special microfibers, rather than coarse bits of gravel and sand, to strengthen the cement.

youdao

他们用特殊的超细纤维来替代粗糙的砂石颗粒，以强化水泥。

They used special microfibers, rather than coarse bits of gravel and sand, to strengthen the cement.

youdao