英语语法分析

While holding down on the cone, tighten the subbase screws.

用手压住漏斗，拧紧座垫固定螺丝。

Loosen but do not remove the subbase screws so that the subbase can move freely.

松开但不要取出座垫固定螺丝，座垫活动了即可。

Regeneration aggregate can substitute natural aggregate and be used for highway base and subbase aggregate.

得出再生集料可以替代天然集料用于高等级公路基层和底基层的结论。