The answer to #1 is A. The answer to number 4 is that identical twins are from one egg and fraternal twins are from two different eggs. I'm sorry I don't know the other ones.
Ok, Heterogeneous mixtures contain one or more elements in the mixture.
Elements are one single species, you want find two different atoms representing one element ever .
Heterogeneous mixture can be broken down and separated i think into components. Element gold is as basic as you can get; it won't break down into anything simpler than gold .
hope this is some info 2 help you well :)