Suppose you are riding on a hot air balloon, carrying a buzzer that emits a sound of frequency f . If you accidentally drop the buzzer over the side while the balloon is rising at constant speed, the frequency and intensity of what you can hear sound as the buzzer falls toward the ground ___________ and __________ respectively. (fill in increases/decreases and use the comma to connect two choices)
举一反三
- Sound discrimination. The two phrases you hear are the same.
- 必须清楚的听到声音。 A: You must hear the sound clearly. B: You must hear the sound distinctly. C: The sound must be audible and not garbled.
- Which of the following is NOT the sound that you can hear if staying in the dark, desolate house described in this piece?
- If you shout loudly, you will hear the ( ). A: voice B: echo C: sound D: noise
- Can you make ______people on the phone by the sound of their voice? A: out B: up C: over D: of