How are some ways i can preserve minerals

Which of the following typically characterizes a tropical rainforests

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.

What if the yeast were extremely active and produced more than 100ml gas. would you know? why/why not