1. (2021·海南模拟) 阅读理解

Tapping into the water cycle and producing electricity from rainy days could be one way to grow our renewable(可再生的）energy use.

Until now, scientists have been unable to get water droplets(雨滴) to produce a large amount of power—but we may finally have a breakthrough. While we're still a long way from umbrellas, the latest approach shows there might be a way to get power from rain showers at a level of efficiency(效率)that makes these systems practical.

New research has found a method that could produce enough power from a single droplet of rain to light up 100 LED bulbs. That's a big jump forward in efficiency in the field.

Scientists have been looking into this type of power production for years, but the physics of converting the energy of raindrops into electricity are much harder to do than getting the energy from a rising tide or a flowing stream.

One of the improvements the team built into their droplet-based electricity generator(发动机)(DEG) was the use of a polytetrafluoroethylene or PTFE film, which is able to accumulate a surface charge as it's continuously hit by water droplets, until it gradually reaches saturation(饱和). The team found that as water droplets hit the surface and spread out, the drops act as a "bridge" that connects two electrodes(电极). The droplet bridge in turn creates a closed-loop surface so that all of the collected energy can be released(释放). This approach could eventually be applied anywhere that water hits a solid surface, the researchers say—the hull of a boat, the inside of a water bottle, or the top of an umbrella. However, there's still plenty of work to do to get this ready for practical use, with the researchers hoping to have a prototype ready in the next five years.

1. （1） What can we infer from the first two paragraphs?

   A . Umbrellas will be of great use in the near future. B . Rainy days have ever been made use of by scientists. C . There's a possibility of making power by using water drops. D . Scientists have made great achievements in using water drops.
3. （2） Which has the closest meaning to the underlined word "converting" in paragraph 4?

   A . Improving. B . Changing. C . Producing. D . Spreading.
5. （3） What's the role of PTFE film according to the passage?

   A . To give off the energy. B . To hit water drops repeatedly. C . To work as a "bridge". D . To collect a charge on the surface.
7. （4） What's the most suitable title for this passage?

   A . A New Way to Produce Electricity from Rain B . The Working Theory of Water Drops C . The Benefits of Using Clean Energy D . The Future Use of Umbrellas