A variety of microorganisms live as symbionts in the human digestive tract. What determines whether their relationship with the human is parasitic or mutualistic?
a their size compared to human cells
b their reproductive rate compared to the replication rate of human cells
c. whether or not they gain energy from food that the human eats
d whether their actions harm or benefit the human host

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the