Science quiz question 2, Thanks if you help!

How does an angiosperm prevent self pollination

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

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.