Can someone answer this please I only need 2 but I'm not sure about the others

Skulls of (1) modern gorilla, (2) australopithecus afarensis, (3) homo erectus, (4) homo neanderthalensis, (5) homo sapiens based on the diagram, which of the following best describes ways in which the physical appearance of h. neandertalensis and h. sapiens differ? (2 points)

In general, are there any major differences that you can see? explain

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.