If you have a control group for your experiment, which of the following is true?
a. the control group is exactly the same as the test group.
b. the control group is identical to each test group except for one variable.
c. there can be more than one difference between the control group and the test groups.
d. the control group and the test groups may have two or more differences between them.

muslims have taken his goods and products to different parts of asia an indonesia. sometimes just traveled and trade, but in other occasions, stayed in the place and made a living.

trade was the key for muslims economies to prosper. their commerce routes reached far places like malaysia and java in the 11th century.

another important factor for prosperity was that muslim states served as the middle point for european traders.

they used to travel by land but sailing the seas -the indian ocean- really increase the exportation of products.

a bad leader