题目内容：

As free as they make us, mobile phones still need to stay close to a power source. Soon that may change with "green" power.

Three Chilean students got the idea for a plant-powered device(装置) to charge their cellphones, while sitting in their school's outdoor courtyard during a break from exams, with dead mobile phones. Then, one of them had an "aha" moment.

“It occurred to Camila to say about plants, "said inventor Evelyn Aravena. "Why don't you have a socket, if there are so many plants? 'After that, we thought, why don't they have a charging outlet? Because there are so many plants and living things that have the potential to produce energy, why not? ' "

Their invention — a small biological circuit called E-Kaia - uses the energy plants to produce during photosynthesis(光合作用). A plant uses only a small part of that energy and the rest goes into the soil, and that's where the E-Kaia collects it. The device plugs into the ground and then into your phone.

"It's the most amazing project I've ever seen in my life, plain and simple. They brought this original model, and it worked — and that's when it all changed, at least from my personal point of view and I began to support them. " said Mauricio Cifuentes.

The device solved two problems for the engineering students — they needed an idea for a class project, and an outlet to plug in their phones.

"Looking for a place to charge the notebook, which had no power, and the mobile phones, we weren't able to find anything because all the other students were in the same state of madness trying to find a place to charge their devices," said Aravena.

But plants are everywhere, and the biocircuit makes the best of their excess(过多的) power.

The E-Kaia doesn't carry much charge but it's powerful enough to completely recharge a mobile phone in less than two hours.

The student inventors have applied for patents on their technology, and expect the E-Kaia to go on sale in December 2016.

1.How could the students get the "green" power idea?

A. By carrying out an experiment.

B. Just from an occasional thought.

C. With the support of their professors.

D. Enlightened(启发) by the information in a science book.

2.How does the device work?

A. By using the energy during photosynthesis.    B. By using a small biological circuit.

C. By using the electricity stored in the device.    D. By using a device buried in the ground.

3.What can we learn from what Mauricio Cifuentes said?

A. He intended to buy the patent.

B. The device was made in a rough way.

C. He showed great interest in the device.

D. He attempted to produce the device in large numbers.

4.What might be the best title for the passage?

A. A New Device to Change the World

B. Green Power - A New and Potential Source

C. Chilean Students Find A Green Way to Charge Phones

D. A New Device Invented by Chilean Students Will Be on Sale