In your own opinion, Discuss something about PC system, Reservation system, Global distribution system (GDS), Central reservation system (CRS) that can be used to book hotels, car rentals, and flight.​

Nuclear experimentation is a major global issue that affects relationships between countries. describe why countries try to limit the testing of nuclear weapons.

What is the result of the greenhouse effect? a. heat is deflected from the atmosphere. b. heat is released from the atmosphere. c. heat is kept in the atmosphere. d. plants are able to grow in the tropics where the air is the heaviest.

Which of the following is evidence to the past existence of glaciers?