What is ostia in biology

Johannesburg kepler, an apprentice of brahe, believed in the heliocentric universe but rejected past astronomers belief in

The source of energy shown in the image is (renewable, non renewable, polluting) a drawback of building a dam is that (it will destroy ecosystems, it requires fossil fuels, it won’t be useful for irrigation)

In what locations does this text suggest you might find zooflagellates living? fresh water lakes on the surface of leaves inside other organisms on damp forest floors