What is genetic engineering? A the manipulation of genetic instructions to produce new characteristics B the creation of a new species that has desirable traits C a process used by natural selection to thin out a population D the breeding between the fittest members to produce multiple offspring

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them