Answer:
A and B.
Explanation:
Hope this helps a little bit.
Geography is literally 'the study of Earth' from 'ge (γη)' meaning earth and 'grapho (γραφω)' to write or to study.
The ninth planet is Pluto, but this was ruled a dwarf planet in 2006. It has a small surface area than Russia.
Abrasion is caused by the effects of wind and sand.
I believe its lack of worthy projects, but ill tell you if im wrong.
A net population decline resulting from an "excess of deaths over births".
Option: A
<u>Explanation</u>:
Demographic transition is a shift from higher to lower level of fertility and mortality.Rapid development in industrialization and urbanization in 
century resulted into enormous population growth. But decline in early 
century covered many reasons like consequences of two calamitous wars, where Europe suffered large population declination due to battle death and civilian causalities in World War I and II. Hence the acceleration of population growth in 19th century but downfall in 20th is also considered as balance.
