题目内容
D. Read the passage and answer the following questions（根据短文内容回答下列问题）
The world is filled with many interesting sounds. Some are unpleasant to our ears while others are very pleasant to hear. In a single day you probably hear hundreds of different sounds. All sounds are different. Some may be loud. Some are high; others are low. Some sounds are useful. Without sound we cannot talk or listen to one another. The ringing of the alarm clock wakes people up. The hooting of a car warns people of danger.
Some sounds are harmful. When planes fly low over the land, the very loud sounds can damage the houses. Very loud sounds can even make people deaf. We know sound travels about one kilometer in three seconds. In a thunder storm you see the lightning first and then hear the thunder. This is because light travels much faster than sound.
Next time you see lightning, count the number of seconds before you hear the thunder. Divide this number by 3. This will tell you how many kilometers away the thunder storm is.
1.All the sounds in the world are pleasant to hear, aren’t they?
2.What may happen when planes fly low over the land?
3.How fast does sound travel?
4.Why do we see the lightning first and then hear the thunder?
5.What’s your favourite sound in the natural world?
