Low maintenance是什麼意思?

1.low maintenance和high maintenance是什麼意思?
還有幾個關於環保的標語
2.Beautify your town
3.Clean up litter
4.Donate your time
5.Volunteer (Work without pay in the fire department, a hospital,or a
school)
6.Donate your organs

這幾個是什麼意思?
3 個解答 3