I think its C building a barrier wall
Answer:
The average atomic mass of X is 206.0346
Explanation:
Atomic mass of 200X = 200.028
% abundance of 200X = 40% = 40/100 = 0.4
Atomic mass of 210X = 210.039
% abundance of 210X = 100% - 40% = 60% = 60/100 = 0.6
Average atomic mass of X = (0.4×200.028) + (0.6×210.039) = 80.0112 + 126.0234 = 206.0346
private property owners in the United States can restrict public access to their land
combustion of fossil fuels would be the correct answer when dealing with the alteration of the carbon cycle.