CLEAN : Tibetans rally outside IOC against Beijing Winter Olympics

The video begins with the speaker expressing gratitude, followed by a discussion on the topic of cold air.

What is the primary focus of the initial part of the video?

• Explaining the properties of cold air

• Expressing gratitude

• Discussing warm air

• Introducing a new topic

Which of the following is discussed in the second section of the video?

• The impact of air pollution

• The history of air conditioning

• The characteristics of cold air

• The benefits of warm air

What is a possible effect of cold air mentioned in the video?

• It decreases temperature

• It enhances air quality

• It causes global warming

• It increases humidity

How does cold air typically move in the atmosphere?

• It moves horizontally

• It sinks downwards

• It remains stationary

• It rises upwards

What is a common misconception about cold air?

• It is lighter than warm air

• It is always dry

• It has no effect on weather patterns

• It is heavier than warm air