题目内容：
根据下面资料，回答题 While you' re in a lift, waiting to reach your floor, do you ever wonder who came up with the
idea? Probably not. We just expect to have safe lifts in buildings.
Lifts existed as far back as ancient Rome. But the ancient "lifts" weren' t closed cars. Theywere simple platforms. They were typically used to raise up water for farming or lift heavy buildingmaterials such as stones. These lifts were powered by animals, people or even water wheels.
The first modern passenger lift Was built for King Louis XV in 1743. The King' s lift was installed(安装) on the outside of his palace. It went from the first to the second floor. The King entered it fromhis balcony, and then men raised and lowered the lift through the use of ropes and wheels.
Lifts became more common in the mid-1800s during the Industrial Revolution when theytransported goods in factories and mines. These lifts were often based on a hydraulic (液压的)system. However, this type of lifts was impractical for tall buildings, although it became popularbecause it could operate with the public water system.
Another lift design (and the one found most often today in passenger lifts) uses a cable system,in which ropes raise and lower the car by means of a wheel and gear (齿轮) system. These types oflifts are easier to control, and buildings that have them do not need the extra room required byhydraulic systems. By the 1850s, these types of lifts had been powered by water pressure or steam.
The lifts in ancient Rome_______. A．had a closed structure
B．had a complicated design
C．were used in agriculture
D．were powered by steam
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