Answer:
c. Observational studies have both independent and dependent variables.
d. Observational studies can be used to test hypothesis.
Explanation:
Observational studies are ones in which a researcher makes observations about his thoughts and views. He observes the risk and other effects before actual test takes place. This is usually the initial phase of research where observations are made for suitability of certain things that are to be researched. There is initial feasibility test conducted to identify whether the further research process is beneficial or not.
<span>About
"20" % of American men and
"23"% of American women have experienced a divorce.</span>
The normal
length of a marriage that closures in separation is eight years. Individuals
hold up a normal of three years after a separation to remarry. Divorce is a
lawful procedure in which a judge or other expert legitimately ends a marriage,
reestablishing them to the status of being single and allowing them to wed
different people.
Europe is one of the smallest continents. Only Australia is smaller. Though small, more than 700 million people live in Europe.
Millions of people live in Europe's large cities. Nearly 12 million people live in Moscow, Russia and more than 143 million people live in Russia. Other large cities include Berlin, Germany, and London, England.
So all in all, most people live in Russia.
A Fertile Crescent, which is a crescent-shaped region that contains very
fertile land around the Tigris and Euphrates Rivers, parts of Asia
Minor, and the Nile River regions.
