题型：阅读选择 题类：常考题 难易度：普通
北京市延庆区2019-2020学年八年级下学期英语期末试卷
Painful for Your Ears
Do you often listen to music at loud volumes? You should know that this habit is bad for your hearing, according to the World Health Organization (WHO).
The human ear has three different parts. The outer ear is the part you can see. The middle ear and inner ear are inside your head. That doesn't mean those parts can't be hurt. They can be harmed by loud noises. Over one billion young people are at risk of hearing loss due to listening to loud noise for long periods of time, said WHO. Listening to music or watching a TV show at loud volumes can harm your hearing.
Sounds are measured in decibels (dB分贝). A whisper is 30 dB. A friend talking is about 60 dB. The sound of a busy road is about 85 dB and the sound of a rock concert can be about 100 dB. The United Nations has standards for safe listening. It is not safe to listen to sounds that are louder than 85 dB for eight hours or 100 dB for 15 minutes.
Loud noise is harmful to the inner ear. Most of us are born with about 16,000 hair cells (听毛细胞) in our inner ears. These cells detect (探测) sounds. However, listening to loud noise for a long time can make these cells work too hard and cause some of them to die. This is what causes hearing loss.
Some people might think that their music isn't all that loud. But this can depend on where you are. For example, if you are in a noisy place like the subway, you might turn up your music too loud without realizing it. Later, when you listen to it the same volume in a quiet place, you might feel uncomfortable.
What can be done to protect your hearing? Use noise-canceling (降噪) headphones. These headphones get rid of background noise. You don't need to turn up the volume as much. Keep your device volume at 50 to 60 percent. Limit daily use of headphones. Listen to sound on your mobile devices for a maximum of one hour per day.
The less loud noise you hear, the better!
Do you know what makes lightning (闪电)? {#blank#}1{#/blank#}
Lightning strikes happen when ice and water in clouds rub (摩擦) together, and cause atmospheric (大气层的) changes. When this happens, it creates a static charge (静电). Lightning can strike inside the cloud, between two clouds or between a cloud and the earth. {#blank#}2{#/blank#}
Lightning can be very dangerous. Every year, lightning kills people because it can start big fires or because it reaches a temperature of 28,000℃. About 1,000 people are hit by lightning every year in the United States, and about 100 of them die as a result.
{#blank#}3{#/blank#}Scientists think that there are more than three million lightning strikes every day in the world. An American man, Roy Sullivan, who worked in a park, survived from the most lightning strikes. {#blank#}4{#/blank#}And he keeps the highest world record.
Lightning is sure not something to play with. When lightning strikes, it's best to stay inside a large building. {#blank#}5{#/blank#}Also, do not lie down on the ground, or the electricity may go through you and cause a heart problem.
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A. It's the last kind of strike that is the most dangerous for humans. B. Lightning makes people shocked, and it happens all over the world! C. Between 1942 and 1977, he was hit seven times! D. Why does lightning strike (击打)? E. To stay safe, do not stand under trees, on hills or near water. |
Kew Gardens Enjoy yourselves in a wonderland of science with over 50 000 living plants and different kinds of educational events or interesting activities. Here is some useful information about planning a school visit to Kew Gardens. Educational session(时段) prices You can plan a self- led visit or book one of our educational sessions. Students will take part in the educational sessions in groups of 15. Prices are different according to different situations. ●45minute session:£35/ group ●90- minute session:£70/ group ●Half day( one session):£ 80/ group ●Full day( two sessions):£ 160/ group Health and safety Required teacher- student ratios(比例): ●Key Stage 1—1:5 ●Key Stage 2—1:8 ●Key Stage 3—1:10 ●Key Stage 4—1:12 If you need help, please contact(联系) the Kew staff members(工作人员). You can also call 0202 332 3333 for direct and quick support. Please do not call 999. Timings The Kew Gardens opens at 10 am. Your visit may take three to five hours. The closing time changes throughout the year. But the earliest is 3:30 pm. We have a fixed schedule for educational sessions, which is from 10:30 am to 2:20 pm. |
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