Answer:Selection bias
Explanation:Selection bias refers to selecting individuals in a way that a proper randomisation is not achieved which makes the result not representative of the whole population. This is also called selection effect.This usually occurs when a researcher chooses only participants that will support the idea he has in mind about the variable of interest that they are researching. For example if someone is researching the effect of healthy food on particular population but instead of selecting participants randomly, a researcher goes to a health food market ,vegetable places and gyms. Then a researcher ends up concluding that healthy eating is crucial within this population.
This is wrong because a researcher only chose places that were convenient to this research.
During Angolan civil war, there are 2 groups who fight for the power in Angola : MPLA and UNITA
The civil war turned into cold war battle ground because the MPLA was supported by Uni Soviet and the UNITA was supported by United States
Because may be they have bad attitudes
