hēimǎ
黑马  

释义
      "黑马"原来是指在赛马场上本来不被看好，却能在比赛中出乎意料地获胜的马匹。后来比喻实力难测的竞争者或出人意料的优胜者。
"黑马(hēimǎ)" refers to the unexpectedwinner in a race or competition. This word is originally used in the field of horse racing.

例句
1、Zhēn méi xiǎngdào, tā chéngwéi le zhè cì yǔmáoqiúsài de hēimǎ.
     真没想到，他成为了这次羽毛球赛的黑马。
     I didn′t expect that he became a dark horse in this match of badminton.

2、Zài zhè cì xuǎnjǔ huódòng zhōng, tā yìjǔ dǎbài le hěnduō duìshǒu, chéngwéi le zhèngtán hēimǎ.
     在这次选举活动中，他一举打败了很多对手，成为了政坛黑马。
      He had beaten all his rivals at the first try and became a dark horse in the election.

• competition [,kɔmpi´tiʃən]   n.比赛；竞争   (初中英语单词)
• beaten [´bi:tn]   beat 的过去分词   (初中英语单词)
• election [i´lekʃən]   n.选举；选择   (初中英语单词)
• unexpected [ʌniks´pektid]   a.突然的；意外的   (高中英语单词)
• originally [ə´ridʒənəli]   ad.本来；独创地   (高中英语单词)
• winner [´winə]   n.胜利者，得奖者   (英语四级单词)