阅读《雪地里的迎春花》回答问题。
         ①我十岁那年，父亲终于决定外出谋生。他说，他得出去挣点钱,以后让我进城念好的学校。他说话时，母亲正倚在门上，用破旧的头巾扑打着身上的灰尘。 
        ②父亲走的这天，母亲没有出门送他。我以为，母亲并不在乎父亲的走与留。殊不知,我却在午后的玩耍中，偶然看到了蹲坐在玉米地埂上的母亲。正独自默默流泪，面前的母亲和一个时辰前与父亲欢笑着告别的母亲俨然判若两人。
        ③父亲回来的那天,隔壁邻居都过来看了。母亲一直不说话，父亲从兜里掏出一枚精致的黄色发卡。我认识，那是一朵多么漂亮的迎春花啊!黄色的蕊，黄色的瓣，如同一只翩翩起舞的蝴蝶。父亲将它插入母亲的发隙中，用手指一按，“啪”一声，别在了头上。母亲于是欢喜地进了厨房，只剩我和父亲在门前嬉闹。
        ④没过几天，父亲又回到城里去了。其间，他给家里写过两封信，说自己在一家公司里做搬运工，货物虽不重，可都是高档货，很能赚些钱，叫我和母亲不要担心。那两封简短的信，不识字的母亲硬是让我念了许多遍。而她每听完一遍，都要在地埂旁坐上很长时间。
        ⑤春节前，母亲收到了父亲的汇款。经过一夜的深思，母亲最终决定带我去城里添置些东西，好给父亲一个惊喜。母亲买了一条羊毛围巾、两张年画和一个偌大的二手衣柜。母亲说，这种衣柜，放在家里够气派。
        ⑥衣柜有了，可搬运成了问题。我们只得花一点工钱，去桥头上雇个搬运工。
        ⑦桥头的工人可真多啊，密密麻麻地聚集了一地。前头的几个老练的小工一看到我和母亲，便迅速起身围了过来。
        ⑧寻思间，一个声音粗犷的男人对着密集的小工打趣：“嘿，是不是又来老板了?找我啊，我力气可大着呢，庄稼人!不偷懒儿!”
        ⑨母亲迅速拨开人群，循声望去。不远处的空地上，坐着一个头发蓬乱，衣衫褴褛的男人。我看不清那张黑黝黝的脸，只是他手臂上特有的疤痕，让我辨认出，他便是我的父亲。他在见到我与母亲的一瞬间，惊慌失措地捂着肚子往远处跑，似乎是急着上厕所。
       ⑩母亲没有叫他，目不转睛地看着那个熟悉的背影渐渐消失在视野里。然后她随便指了一个在旁的男人，拉着我，飞也似的离开了。我气喘吁吁地抬头，看到母亲那簌簌滴落的眼泪打湿了那条新买的羊毛围巾。
       ⑪父亲出事的那天，母亲正在门前扫雪。一个神色匆忙的男人从马车上跳下来说：“不好啦，不好啦，虎子他爹出事儿了!”
       ⑫父亲是在搬运家具时出事的。楼梯上有水结了冰，父亲一时没有站稳，摔了下来。那张一百多斤重的八仙桌，便毫不留情地砸向了他的身体。
       ⑬父亲最终没能救活。抬棺那天，母亲盘起了头发。将那朵柔黄的迎春花缓缓插入了发际。我没有哭，母亲也没有。
       ⑭亲朋散去之后，我和母亲默默地收拾家里的残局。洗碗时，她捋着蓬乱的头发惊呼：“我的发卡呢?我的发卡呢? ”
      ⑮当夜，母亲硬拉着我，在漫天的雪花中，寻找父亲送她的那一枚黄色发卡。我从来没有见她如此疯狂过。
      ⑯大雪呼啸着席卷了山野。漆黑的夜，路上，我和母亲趴跪在冰凉刺骨的雪地上，一步一步地顺着掩埋父亲的方向找寻而去。
      ⑰母亲的发卡真丢了。父亲下葬时，她不曾哭泣，如今却在惨白的雪夜里，为一枚没有生命的发卡哭得没了声息。
      ⑱当雪花再度悄然覆盖了村庄，我已不觉寒冷。因为我知道，在这个白雪皑皑的世界里，一定有一枚温热的发卡在寒冬的深处，默默地守护着一朵柔黄的迎春花。                                           

如图所示，某同学为了找出平抛运动物体的初速度之间的关系，用一个小球在O点对准前方的一块竖直放置的挡板，O与A在同一高度，小球的水平初速度分别是v₁、v₂、v₃，打在挡板上的位置分别是B、C、D，AB：BC：CD=1：3：5．则v₁、v₂、v₃之间的正确关系是（   ）

    In the mid-nineteenth century, as iceboxes became increasingly common in American homes, there were efforts to find cheaper and more reliable sources of ice. In the eighteen-thirties, scientists discovered a way to make ice, which is similar to how a refrigerator works. In 1860, there were four artificial-ice plants in the United States; in 1889, there were about two hundred; by 1909, there were two thousand. Ice now came from factories, not ponds, and it was turned out in three-hundred-pound blocks by lowering steel cans of pure water into tanks of refrigerated salted water. Kept below thirty-two degrees, the salted water did not freeze, but the water in the cans did. Those cans were then lifted from the tank, and the ice was taken out of them.

    The ice blocks were delivered to home users, and to the fishing and chemical industries. On the railroads, trains carrying fruit and vegetables had cars at each end filled with blocks of ice. It was a growing industry.

    The great trade began to fall away in the middle years of the twentieth century. The railroad business shrank, and, in the immediate postwar period, block ice lost out to home refrigerators and then to small commercial ice machines. By the nineteen-sixties, things looked very dark. “It was scary,” Dan Ditmar, an ice expert in San Antonito, told me. “Your biggest customers were cafeterias and country clubs, and you'd go out there and they'd say, 'We don't need you anymore; we've got ice machines.'”

    Then the companies that survived the slump（a slump is a period when there is a reduction in business）began investing（投资）in newly developed ice-cube machines, and by the late sixties American ice was becoming a packaged-ice business. And packaged ice was exactly what the country needed. These were years of increased leisure time—more barbecues, more cars, and more houses by the lake. “Things exploded in the nineteen-seventies, Paul Handler said. Ice cubes evolved. They became hugely popular^ shoveled（铲）here and there into picnic coolers and fast-foof sodas. They became noisier.