Pls help! Will mark brainliest!

To be considered they must have lived over a very short period of time and had to be many of them.

A) An index fossil
B) A trace fossil
C) A petrified fossil
D) A carbon fossil

Connect the whole numbers on the periodic table to indicate what they represent?

40dm3 of gas at 760 torr are heated from 5°c to 50°c what is the new volume

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.