过空间任意一点引三条不共面的直线，它们所确定的平面个数是(    )

下列关于物体重心的说法正确的是（　　）

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        第二天，中午的时候，非常闷热。一轮红日当天，水面上浮着一层烟气。小火轮开得离苇塘远一些，鬼子们又偷偷地爬下来洗澡了。十几个鬼子在水里泅着，日本人的水式真不错。水淀里没有一个人影，只有一团白绸子样的水鸟，也躲开鬼子往北飞去，落到大荷叶下面歇凉去了。从荷花淀里却撑出一只小船来。一个干瘦的老头子，只穿一条破短裤，站在船尾巴上，有一篙没一篙地撑着，两只手却忙着剥那又肥又大的莲蓬，一个一个投进嘴里去。
他的船头上放着那样大的一捆莲蓬，是刚从荷花淀里摘下来的。不到白洋淀，哪里去吃这样新鲜的东西?来到白洋淀上几天了，鬼子们也还是望着荷花淀瞪眼。他们冲着那小船吆喝，叫他过来。
        老头子向他们看了一眼，就又低下头去。还是有一篙没一篙地撑着船，剥着莲蓬。船却慢慢地冲着这里来了。
小船离鬼子还有一箭之地，好像老头子才看出洗澡的是鬼子，只一篙，小船溜溜转了一个圆圈，又回去了。鬼子们拍打着水追过去，老头子张皇失措，船却走不动，鬼子紧紧追上了他。
        眼前是几根埋在水里的枯木桩子，日久天长，也许人们忘记这是为什么埋的了。这里的水却是镜子一样平，蓝天一般清，拉长的水草在水底轻轻地浮动。鬼子们追上来，看看就扒上了船。老头子又是一篙，小船旋风一样绕着鬼子们转，莲蓬的清香，在他们的鼻子尖上扫过。鬼子们像是玩着捉迷藏，乱转着身子，抓上抓下。
        一个鬼子尖叫了一声，就蹲到水里去。他被什么东西狠狠咬了一口，是一只锋利的钩子穿透了他的大腿。别的鬼子吃惊地往四下里一散，每个人的腿肚子也就挂上了钩。他们挣扎着，想摆脱那毒蛇一样的钩子。那替女孩子报仇的钩子却全找到腿上来，有的两个，有的三个。鬼子们痛得鬼叫，可是再也不敢动弹了。
        老头子把船一撑来到他们的身边，举起篙来砸着鬼子们的脑袋，像敲打顽固的老玉米一样。
        他狠狠地敲打，向着苇塘望了一眼。在那里，鲜嫩的芦花，一片展开的紫色的丝绒，正在迎风飘撒。
        在那苇塘的边缘，芦花下面，有一个女孩子，她用密密的苇叶遮掩着身子，看着这场英雄的行为。

    Years ago, I lost my sight completely. I would do anything for a 1 . In fact, desperate and 2 , I tried every supplement, experimental trial, diet and anything anyone 3 . All for nothing.

    But now, after 25 years in physical darkness, my life is 4 than ever. The change began one day, many years ago, when I drank my tea 5 , swallowing gulps(一大口) of “poor me” and wondering what my future would 6 . Then, the doorbell rang. Janet came in and brought an idea. “Have you ever thought about working as a(n) 7 ? ” she said, “You speak Spanish. Go for it.”

    Her idea 8 me to make a phone call. And the interpreting company I contacted invited me to take a test. Thank goodness it was 9 .

    “We're so 10 with the results,” the receptionist said the next day, “that we want to send you on your first 11 tomorrow. It's in the Immigration and Naturalization Court.”

    That was the beginning. That was when I began to 12 possibilities when my blindness wouldn't get 13 . The view of my world had changed. Blindness didn't have to label me as

    14 . On the contrary, the blindness improved my ability to 15 information and present a quicker and more 16 interpretation.

    The letters from judges, praising me for my work, 17 me for the hours I'd spent studying, memorizing, and 18 .

    Blindness? Not a barrier any more. 19 , it became a handy 20 to sharpen my creativity. Not only in the courtroom, but at home, in my relationships and in the way I viewed myself.