K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
VP
1
23 tháng 4 2017
As a senior high school student, I am very busy with my studies. Although I am very fond of watching television, I can only spend an hour after dinner on my hobby. Of all the TV programs, I like the news and documentaries best.
The news programs shown on all TV channels at 7:00 p.m. help me to know almost everything about different places in our country and important events happening all over the world. Through these programs, I can also know about the main national and international sporting events.
The documentary programs at weekends are my favorites. By watching them, I can learn a great deal about human civilizations, the wonders of nature and the amazing inventions and discoveries of great people in the world.
Watching television is my hobby. I cannot imagine a day in my life without watching it.
19 tháng 4 2017
Electric Cars
Hybrids vehicles, with their combination of both gas and battery power, represent 3% of the cars on the road today, up from zero just ten years ago. Fully electric cars like the Nissan Leaf and Tesla are mere curiosities, representing only 0.1% of all cars purchased in the U.S.
It might seem like a slow start, but electric cars will soon form the majority of all vehicles. Here’s why:
Except for early adopters of technology and diehard environmental customers, most people aren’t buying a fuel type, they’re buying transportation. They may want speed or economical transportation or family-friendly minivans, but how the vehicle is powered isn’t their main concern.
Examples like the Tesla have shown that electric vehicles perform on par with gas-powered cars. What limits their adoption then? Two factors: cost and range (and charging infrastructure, to a lesser extent, but that will be remedied when there is more demand).
The Nissan Leaf battery pack alone costs about $18,000 (though government incentives bring down the overall vehicle cost to the customer). When comparable gas-powered cars are about $20,000, the high cost of the battery pack alone is a huge barrier to widespread adoption, whether the cost passed on to the customer or the government, or hidden by the manufacturer.
Ramez Naam, author of The Infinite Resource: The Power of Ideas on a Finite Planet, recently explained that lithium-ion batteries have a fifteen year history of exponential price reduction. Between 1991 and 2005, the capacity that could be bought with $100 went up by a factor of 11. The trend continues through to the present day.
This exponential reduction in battery cost and improvement in battery technology, more than anything else, will affect both the cost and range of electric cars. By 2025, that Nissan Leaf battery pack will cost less than $1,800, making the cost of the electric motor plus battery pack less than the price of a comparable gasoline motor. Assuming even modest increases in storage capacity, the electric vehicle will rank better on initial cost, range, performance, and ongoing maintenance and fuel costs.
With both lower cost and better performance, electric vehicles will likely overtake gasoline-powered ones by about 2025.
TT
Help me
1
LQ
6
27 tháng 1 2017
thank you very much. Best wishes to you , happy new year.
1. Do more exercise
2. Sleep more
3 Eat less junk food
4. Wash your hand
5. Watch TV less
6. Spend less time play computer game
trường bạn học có vẻ hơi chậm trường mink sang u3 rùi
mai học òi m.n ơi.