What is sceince is the mean explanation​

15 points come and ! which characteristic describes all bacteria? a rod-shaped b microscopic c multicellular d autotrophic

Acommon kind of mechanical weathering is called

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?