Most GUYS already understand the general concept of trees. Even though they might not be able to explain photosynthesys in detail.
to make a sweeping generalization. (usually used in the negative: 一概には言えない (I don't want to generalize, but. . . ) )
When duty calls I GO to obey.
A yo-yo dangles from a vertical STRING, and sways.
I deplore with all my HEART the general concept of cutting down TREES.