Which plant tissue transports sugars from the leaves of a plant back to the roots for storagea. xylem  b. chloroplastsc. phloem  d. meristem

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

I’m stuck on this question cuz i’m stupid sksksksk

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?