单选题
{{I}} Questions 11～13 are based on the following passage. You now have 15 seconds to read questions 11～13.{{/I}}
【正确答案】
【答案解析】 [听力原文] <11>-<13> Man's first real invention, and
one of the most important inventions in history, was the wheel. All
transportation and every machine in the world depends on it. The
wheel is the simplest yet perhaps the most remarkable of all inventions, because
there are no wheels in nature - no living thing was ever created with wheels.
How, then, did man come to invent the wheel? Perhaps some early
hunters found that they could roll the carcass of a heavy animal through the
forest on logs more easily than they could carry it. However, the logs
themselves weighed a lot. It must have taken a great prehistoric
thinker to imagine two thin slices of log connected at their centers by a strong
stick. This would roll along just as the logs did, yet be much lighter and
easier to handle. Thus the wheel and axle came into being, and with them the
first carts.
单选题
What does the passage tell us about the wheel.