The answer is petroleum
hope this helps!
Answer:
health, traditions, economic base. hope this helped!
God bless!!
Bhutan is a very unique country. ... Bhutan is the land of happiness on earth. People may not be very rich, but they are happy. The country where Gross National Happiness (GNH) is valued more than GDP will always be special.
The degree of vertex D is if it is an indegree or outdegree, it is 1 degree in vertex D.