What must happen before la a chemical reaction can begin

Mention true or false : a) cholera is marked by acute diarrhea and no urination. b)mosquitoes are the source of dysentery germs.

Drag each label to the correct location on the table. each label can be used more than once. decide whether each statement describes saturated fat, unsaturated fat, or both saturated and unsaturated fats.

Why are fossils not found in igneous rocks? igneous rocks are made from cooling of lava or magma. igneous rocks are found too deep underground. igneous rocks are too dark in color to contain fossils. igneous rocks are too dense to contain fossils.