This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

[EX Q]: LED lamps have been advocated as the newest and best environmental lighting method. According to the Energy Saving Trust, LED lamps use only 10% power compared to a standard incandescent bulb, where compact fluorescent lamps use 20% and energy saving halogen lamps 70%. The lifetime is also much longer up to 50,000 hours. A downside is still the initial cost, which is higher than that of compact fluorescent lamps.
[EX A]: How much more power does a standard incandescent bulb use compared to LED?

[EX Q]: Bell and his partners, Hubbard and Sanders, offered to sell the patent outright to Western Union for $100,000. The president of Western Union balked, countering that the telephone was nothing but a toy. Two years later, he told colleagues that if he could get the patent for $25 million he would consider it a bargain. By then, the Bell company no longer wanted to sell the patent. Bell's investors would become millionaires, while he fared well from residuals and at one point had assets of nearly one million dollars.
[EX A]: How much did Bell et al. try to sell his patent for?

[EX Q]: The first BeiDou system, officially called the BeiDou Satellite Navigation Experimental System (simplified Chinese: ; traditional Chinese: ; pinyin: Beidou weixing daohang shiyan xitong) and also known as BeiDou-1, consists of three satellites and offers limited coverage and applications. It has been offering navigation services, mainly for customers in China and neighboring regions, since 2000.
[EX A]:
What was the first BeiDou system called?