Tornadoes are most frequent during the spring
The correct answer is; D. social science
Social science is NOT a branch of natural science.
Social science is the study of society, the relationship among people in a society and how the behavior of people influences the society. Social science is not a branch of natural science. Social science covers a wide range of disciplines such as economics, psychology, management and business studies, sociology, political science, communication studies and linguistics.
I am unsure of how to answer this completely, but I will give it my best.
It could be meant that there is no physical boundary holding them apart and that the world's oceans simply flow into each other rather than being separated. Such as the pacific and Atlantic. They are not held apart, they flow around countries and flow into each other at a certain point.
Deserts? I mean i don't know the choices.