选择城市
距离2015年6月13日的大学英语六级考试时间越来越近了，听力也需要在短期内得到迅速提升，下面为大家整理了部分英语六级听力真题模拟练习题，希望对大家有帮助。点击下载真题音频
According to the patent application published by the U.S. Patent Office, Amazon plans to use the Global Positioning System, or GPS, not only for deliveries to homes around the country, but directly to purchasers, wherever they may be.
Focusing on the location of the customer's mobile device, usually a smartphone, the drone will be able to avoid both living things and inanimate obstacles,identify areas safe for landing and deliver the package within 30 minutes.
For security reasons,the Federal Aviation Administration requires the drones in this experimental test period to remain within sight of their operators,which severely limits their reach.
Amazon is working on solutions, says Loretta Alkalay, from Vaughn College of Aeronautics and Technology in New York, speaking by Skype.
“I think that they are going to work on those in parallel with advancing the new technology.So I don't see the security problems as being something that should stop the technology."
Amazon is still not advertising the drone deliveries, but Alkalay is optimistic that they will happen.
“I do think that in the reasonably foreseeable future they are going to start doing deliveries.We have already seen deliveries being done in disaster areas and remote areas.I think there is a huge demand for that type of delivery."
There are still a number of concerns regarding possible collisions with various objects, as well as vandalism and theft of the drones and goods, but Alkalay says the media has assumed-incorrectly-that deliveries would be made to people's front doors.
“If you think of a drone delivery perhaps to your rooftop, then you'll have an opportunity to separate the pedestrian and vehicular traffic, and at the same time separate it from air traffic."
Alkalay says even though American homes are not set up for rooftop deliveries,it is possible that future homes will have special platforms for air deliveries of small merchandise.
》》更多精彩冲分课程推荐：
(责任编辑：田学江)
