POV: ur trying to get free points

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

Drag each tile to the correct box. arrange the layers and faults from oldest to youngest.

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.