Why do sociologists need to be careful when drawing conclusions from twin studies?
the results do not apply to singletons.
the twins were often raised in different ways.
the twins may turn out to actually be fraternal.
the sample sizes are often small.

The correct answer is "The sample sizes are often small". Socialization is not only important because it helps uphold societies and cultures, but also because it is a key part of individual development. Sociology is more interested in the way that society's influence affects our behavior patterns.

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.

a would be the answer