Living in the Environment 18th Edition by Tyler Miller,Scott Spoolman

تمرين 11

If you could say hello to a new person every second without taking a break and working around the clock, how many people could you greet in 1 day How many in a year How long would it take you to greet the 84 million people who were added to the world's population this year How many years would it take you to greet all 7.1 billion people on the planet