How does top-down processing differ from bottom-up processing?

Check all that apply diatoms are marine algae that have a shell made of silica, what are some of the uses of the silica shell after the diatoms die? 1.the shells make up the diatomaceous earth used in filters 2.it can be used as an ingredient in abrasives 3.they are used in food products 4.the shells can be used in some insulating materials

Describe characteristics of a good respitory surface

At which point is crust neither created nor destroyed? island chain mid-ocean ridge divergent boundary transform boundary