某导体中的电流随其两端电压的变化如图所示，则下列说法中正确的是（   ）

阅读下面的短文，完成问题。
                                                                                                                                               心 泉
        ①初读王维的《山居秋暝》时，我浸在晶莹的碎得满地的月光中，寻找“清泉石上流”的意境，凝神倾听清澈的声音潺潺地淌过石头，然后又隐隐约约地流向远方。从此，这一涧清泉，便在我生命的最深处。
        ②泉是古诗文中极富韵致的意象。漫步在唐诗宋词明清小品里，耳畔不时传来冷冷的泉声，眼前晃动的是一溪甘冽鲜洁的清泉，以及观泉、听泉者的身影。这身影，杂夹着青石、鸟影、梅枝，掺和些月光、清风、松色。
        ③我曾许多次在旅途中邂逅泉，泉水像那些绿色透明的藤蔓，不时地从脚下的石缝里爬出，从头顶的峭壁上挂下来，或滴珠，或一线，或几绺，或成瀑。它在大地上漫步行走时，随时随地会把不同形状的山体的不同情态，用水质的声音演奏出来，像琴，像笛，像钟，像磐。发出的铮铮泉水声是人间最美的音乐。立于澄澈的泉边，让泉水映照着身影，我掬泉浣面，饮泉入腹，以泉为镜，发现微涩的一张脸已“水色”丰足。
        ④东山魁夷说：“人人心中都有一股泉水，日常的烦乱生活，遮蔽了它的声音。”人生的生存秩序——结婚、生子、柴米油盐等等淹没了它的身影。人之一生，苦也罢，乐也罢，得也好，失也好，最要紧的是心间不能没有一泓清泉。清泉从地层深处喷涌而出，历尽了脱胎换骨的磨砺，只剩下一身的清白。它是尘世间最纯净的东西。从古到今，它不间断地流淌着，阅尽世间一切生物的生死荣枯。它何曾因风霜雨雪而萎缩移易，又何曾因宠辱得失而抛却自适自得。眼中有泉的人，心中亦应有泉。心中有泉才能甘于清贫，甘于寂寞，自始至终保持独立的人格；才能做到一步一个脚印的攀登，不变心性；也才能有诗人的神韵和学者的品性。心中有泉的人，一生都在用心泉浇灌真善美之花。他们为人类留下了夹着热血带着体温的生机勃勃的精神的清泉，屈子字字珠玑的楚辞；李白气概奇伟的诗歌；东坡闳肆奔放的散文；司马迁的传记，黑格尔的哲学，莎士比亚的戏剧，贝多芬的钢琴曲，梵高的绘画……这些历尽磨难的艺术家以精神的清泉赋予人类文明以尊严与高贵。也有一些心中有“圣泉”的人，以其化育万物的慈爱熔铸一个民族的精神，譬如孔子，释加牟尼，还有圣雄甘地。
        ⑤这些源于高贵的心灵的精神清泉，汩汩流进我的心灵，源源不断地渗入我的肌肤与内脏，在我的血管里流淌。它洗去我肺腑中的浑浊，还我以洁净；它冲刷我骨子里的怯懦，还我以刚健；它扑灭我脾脏里的躁火，还我以平和。它疏通血脉，打通经络，以便我更和谐灵敏地感应大地与天宇的生命潮汐。我呼吸天地的湛然清气与浩然正气。清泉流入我的身体，我会从心灵深处听到絮絮低语的泉声。每逢在人生的旷野上迷失，我会观照着流泉的走向，寻找前进的方向。
        ⑥奔波于万丈红尘中的芸芸众生，心中都有一汪清泉。只因尘世的琐碎，生活的纷杂，才遮掩了它的清碧透明。生命不能承受无泉之痛，真正优秀的人生更是如此。现代人的心灵缺少清泉。这种清泉是要自己去创造的，就像爱。我等凡俗之人，当用淡泊宁静的心怀澄清心泉，用心泉冲刷人欲物欲，用心泉涤尽如尘的烦扰。
        ⑦观照心泉，让思想走向深刻，走向纯净；倾听心泉，让生活愈加鲜活，愈加丰盈。更重要的是创造心泉，创造精神的心泉。人生之美，正在于此。

阅读理解

    What would it be like to walk on Mars? If you could build the highest building in the world，what would it look like? Do you dream of being the next J. K. Rowling? This summer, you can experience all of these things, and more. All you need is an Internet connection and your imagination.

    A recent study by the Kaiser Family Foundation found that kids spend an average of 1 hour and 29 minutes online each day. Many kids like to use that time to chat with friends, play games or check e­mails. But the next time you get on the Web, try exploring the world instead. “With the Internet，you can go back 11,000 years in time，or go 11,000 kilometers across the planet.” said Russell, Web search expert of Google. “The whole scope of history and the world is open to you.”

    There is a wealth of information to be found online. For example, if your family is going on vacation somewhere, do a quick online search on the area before you even get in the car. “What's the background of the place; what's the history？” says Russell. “I like to tell my kids, ‘Whenever you have a question, whenever you have a doubt, search it out.'”

    Ready to launch a virtual journey of your own? Here are a few starting points to get you thinking and to help you on your way. You can invite your parents along for the ride, too. Always ask for permission before downloading programs and software onto your computer. And check with a parent or an adult before visiting any new Web site.

    Navigate the world in 3­D with Google Earth. Begin in outer space and zoom (快速移动) into the streets of any city, from Hong Kong to San Francisco. Or visit ancient monuments, watch the changing rainforests over time, and dive underwater to explore tropical reef.

    With the Moon in Google Earth tool, you can walk in Neil Armstrong's famous footsteps. Take a guided tour of the moon's surface with Armstrong's fellow shuttle mate astronaut Buzz Aldrin.

    When you're exploring that part of the solar system, hop on over to the Red Planet with Google Mars. There, you can move very quickly around the surface and see images from the Mars Rovers.

（1）写出物质的化学式：①氧化铝____ ；②锰酸钾____ ；

（2）写出反应的化学方程式：①甲烷燃烧：____ ；②用氯化铜溶液处理纸厂废液中的氢氧化钠的反应：　____ ．