Answer:
true, the alternative would be postzygotic barriers.
Explanation:
There are 4 electrons altogether shared between carbon atoms in a molecule of C2H4, to be more precise there are 2 electron pairs shared between the carbon atoms.
Answer: C) They can contain contaminants that can enter the air during storms or high winds.
Explanation: A is wrong because I got it wrong (Sorry, can't give much explanation there).
B is wrong because water contamination does not directly relate to respiratory health.
D is wrong because fertilizers can impact respiratory health (Explanation seems lack-luster, but I feel like this is common sense).
Hope this helps :)
Page 1:
1. 4th option
2.the 3rd option
3.the 1st option
4. the 2nd option (i think)
5. 3rd option
page 2:
1. 3rd option i think
2.3rd option
3.2nd option
4.2nd option
5.3rd option (i think)