16.Uruk was just one of the large rich city-states of Mesopotamia that had grown too big and too complex for anyone to be able to run them just by word of mouth.
17.To complete a project this big requires the talents of many artists, so Williams put out a call to filmmakers on the Sonnet Project’s website and by word of mouth.
18.He derived that scant information by word of mouth, mainly from an envoy who had visited Pizarro's force for two days while it was en route inland from the coast.
19.However, as it must be done, he had no choice but to do it; so, after attempting several letters, and failing in them all, he resolved to do it by word of mouth.
20.I couldn't very well tell it to your lady friend, and should much have liked to let you know it by word of mouth, as I could have explained better than by letter.