CLEAN : Fireworks explode over Maracana stadium for Rio opening ceremony

The video focuses on the sound of the ground shaking, emphasizing its impact through repetition. It highlights the importance of sound in understanding environmental changes.

What is the primary sound described in the video?

• The sound of water flowing

• The sound of ground shaking

• The sound of birds chirping

• The sound of wind blowing

How many times is the sound of ground shaking mentioned in the first section?

• Four times

• Three times

• Twice

• Once

What is the focus of the second section of the video?

• Introduction to new sounds

• Discussion on sound waves

• Reiteration of the sound of ground shaking

• Analysis of sound frequencies

In the conclusion, what is emphasized about the sound?

• Its origin

• Its repetition

• Its volume

• Its frequency

What is the duration of the final section?

• 10 seconds

• 15 seconds

• 20 seconds

• 30 seconds