(4) Small plants, for example lichens, grow on rocks and produce chemicals that cause weathering.
(4) Small plants, for example; grow; L:on rocks) (4) Small plants, for example; produce; chemicals that cause weathering) (chemicals; cause; weathering)
4) Small plants, for example 4) Small plants, for example chemicals
grow produce cause
L:on rocks
chemicals that cause weathering
weathering