A disturbance would be things like lava, flows, newly formed sand dunes, or rocks left from a retreating glacier. These are disturbances because Primary Successions happen in lifeless areas, which soil is incapable of sustaining life.
stratus cirrus and cumulus
People used vaccines to reduce the risk of infection by working with body as defenses to help them so this vaccines develop immunity to disease
I hope that's help:0
They Are Called Sound Waves.
This is what lets our ears hear "Listen" To noise
i hope this helps you
