Mya Le Thai is a scientist studying at the University of California, Irvine. She recently discovered a process that may result in batteries that last forever. Thai said she had been discouraged that the batteries for her wireless devices degrade. Over time, they fail to charge fully.

    Thai did not like to have keep her wireless laptop connected to an electrical outlet. She decided to do something about that problem.

    At first, she and her team thought about inventing a new battery. But as they experimented, Thai discovered something that might permit lithium-ion(锂离子) batteries to last forever. Lithium-ion batteries power most wireless devices. Over time, the batteries lose the ability to hold a charge. Most of these batteries have a life span of about 7,000 charging cycles before they die.

    One of the reasons lithium-ion batteries degrade is their use of nanowires(纳米线) to carry electricity. Nanowires are extremely thin. A human hair is thousands of times thicker, for example. Nanowires are extremely efficient carriers of electricity, which makes them useful in batteries. But Thai said their thinness also makes them weak. "Nanowires break over time," she said. "That's why they lose capacity."

    But, Thai had a theory: The nanowires might last longer if covered with a material. She and the team tested her theory. The team tried many coverings for the wires. PMMA was one of them. The nanowires were coated with PMMA and cycled through charges 200,000 times. The PMMA coated nanowires showed no evidence of damage. The results suggest that batteries could last forever, without losing charging ability.

    Thai hopes to continue her research to understand why this material works so well and to see if any other material could create better results.

"It's kind of cool," she said. "I'm really glad people are showing interest in my work and not just in the work itself, but also in technology and energy."

阅读A篇短文，从每小题所给的四个选项中，选出能回答所提问题或完成所给句子的最佳答案，并将答题卡上对应的选项涂黑.

    Welcome to the Painting Competition for Woolands Students.

The International Anti﹣Drug Day this year is coming soon. In order to raise teenagers awareness to fight against drug taking. The seat on the council is going to hold a painting competition for the students in our city.

    Students who want to take part in the competition can hand in their own 2D paintings in either of the following two ways:

Each school will be provided with a box for students to put in their paintings. Boxes will be picked up by the City Art Council on Thursday, July 23rd, 2016, before the end of the school day.

    Paintings can be also handed in on Friday, July 24th, from 8: 00am to 10: 00am at the Woodlands Art Hall.

    Or paintings are required to be, 60cm wide by, 80cm long, or smaller. Larger sizes of you not be accept. Each student can only hand in one painting.

The final decision on the competition results will be made on June 26th, the Anti﹣Drug Day. The name list of the winners will be made known on the website of the City Art Council on the same day. All women paintings will be shown to the public at the City Youth Park from June 27th till the end of July.

Prize: 1st Prize（10students）=﹩300GiftCardeach.

2ndPrize（20students）=﹩200Gift Card each.

3rd Prize（30students）=﹩100Gift Card each.

For further information: Visithttp://www. woodlandsartcouncil. org. cn

call 2569﹣8632.

下图是元素X的原子结构示意圈．下列说法正确的是

一位知名的篮球运动员，因为个人素质突出被一家外国的俱乐部选中，不仅能提高个人技术，还能增加收入。临行前，有关方面要求他签一个协议，即承诺在国家需要时，必须回国代表国家参加比赛。这意味着届时他必须中断自己的国外的比赛，在某种程度上就有可能影响自己的国外的发展。

阅读材料，结合所学知识回答问题：