Read the passage carefully and choose the correct answer to each question out of the four alternatives and fill in the blanks.
How the domestication of animals began is not known. Perhaps, there were large numbers of animals in areas near water where men also were (i). Here man could observe the animals and study their habits, and this knowledge must have, (ii) him to tame them. It was again, easy for an (iii) people to domesticate animals and feed them on the husks of the grain that were left after threshing. In any event, sheep and goats, pigs and cattle and later horses and asses were tamed and kept in pens. Man, thus (iv) food from the soil and also from animals. In the pens, the animals could be observed even more closely. Calves suckling milk must have given man the idea that he too could get food other than meat from cows and goats. This practice which combines agriculture with the raising of animals is known was (V) farming. Animals, however, were chiefly used to provide meat and milk, they were yet to be used as beasts of burden or to draw the plough.
(i) = ?

• amassed

• concentrated

• strengthened

• strengthened