Which of the following statements about human settlements and communication are true? (Select all that apply)

a) Early human beings built their homes near rivers because the water was essential for both drinking and farming.

b) Temporary settlements are occupied for short periods and are often found in deep forests, deserts, and mountains.

c) Modern means of transport such as Aeroplanes have made travel from one country to another extremely time-consuming.

d) Developments in communication technology, including the internet and cellular phones, have made it possible to communicate instantly and efficiently across the world.