How did earth cool down enough to sustain life

Sarah is sitting at the top of the slide in the schools playground. which will increase sarah’s kinetic energy a- an additional child is added to the top of the slide. b- sarah is pushed and moves down the slide. c- sarah climbs down the ladder and off the slide. d- the ladder is moved to the other side of the yard.

Select the correct answer from each drop-down menu proteins are

Consider the following reaction: 2h2 + o2 —> 2h2o a) what are the reactants in this reaction? b) what are the products in this reaction? c) how many molecules of oxygen are used in this reaction?