The Radio waves are reflected back to Earth in the Ionosphere which is an electrically charged layer of the upper atmosphere. This process is used to communicate beyond the horizon, at intercontinental distances, mostly in the shortwave frequency bands.

Correct Option: A

The Radio waves are reflected back to Earth in the Ionosphere which is an electrically charged layer of the upper atmosphere. This process is used to communicate beyond the horizon, at intercontinental distances, mostly in the shortwave frequency bands.

A wind rose is a graphic tool used by meteorologists to give a succinct view of how wind speed and direction are typically distributed at a particular location.

Correct Option: A

A wind rose is a graphic tool used by meteorologists to give a succinct view of how wind speed and direction are typically distributed at a particular location.

Typhoons are common in the China Sea and along the margins of the west Pacific Ocean.

Correct Option: B

Typhoons are common in the China Sea and along the margins of the west Pacific Ocean.

The troposphere is the lowest portion of Earth's atmosphere. The average depth of the troposphere is approximately 17 km (11 mi) in the middle latitudes. It is deeper in the tropics, up to 20 km and shallower near the Polar Regions, at 7 km in summer, and indistinct in winter. It contains approximately 80% of the atmosphere's mass and 99% of its water vapor and aerosols.

Correct Option: D

The troposphere is the lowest portion of Earth's atmosphere. The average depth of the troposphere is approximately 17 km (11 mi) in the middle latitudes. It is deeper in the tropics, up to 20 km and shallower near the Polar Regions, at 7 km in summer, and indistinct in winter. It contains approximately 80% of the atmosphere's mass and 99% of its water vapor and aerosols.

The term "smog" was first used in London during the early 1900's to describe the combination of smoke and fog. What we typically call "smog" today is a mixture of pollutants but is primarily made up of ground-level ozone.

Correct Option: D

The term "smog" was first used in London during the early 1900's to describe the combination of smoke and fog. What we typically call "smog" today is a mixture of pollutants but is primarily made up of ground-level ozone.