Which correctly describes measuring the period in transverse and longitudinal waves?

Which macromolecules are polymers made of nucleotides (a) fatty acids (b) nucleic acids (c) carboxylic acids (d) amino acides

What did the first language sound like

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