1、have a right to do sth. 有权做某事
right:① 当名词用，可有复数形式如：human rights；
但是当方向（右边）讲时，不可数，turn to the right向右转
② 当形容词：a.右面的、向右的、上右倾的；
b.对的、正确的、合适、恰当、正当；
c.对头、没事了。如：
He didn’t feel quite right. 他感觉不太舒服。
Your advice is right. 你的建议是对的。
Which is the right answer? 哪个答案正确？
③ 当副词用，向右
Don’t forget to turn right when you meet a bookstore. 看到那家书店别忘了向右转。
The crowd divided right and left. 人群走散了（各奔西东）。
2、have/find + difficulty/trouble + (in)doing sth ./ with sth.
There be + difficulty/trouble + (in) doing sth./with sth.
做某事有困难/麻烦；在……方面有困难/麻烦
其中的 difficulty 和 trouble 为不可数名词；doing 前的介词in 可省略。
①I have some difficulty(in)pronouncing some English words. 有些英语单词我发音有困难。
②Everyone in the town knew him; so we had no difficulty(in) finding his house。
镇上所有的人都认识他，所有我们毫不费力就找到了他的家。
③The boy had little difficulty with maths. 这孩子学数学没困难。
④There was much difficulty (in) finding him. 好不容易才找到他。
3、have mercy on / upon sb.
该短语意为“宽恕（或可怜）某人”，类似的词组还有show mercy to sb.
He always has mercy on the poor.
at the mercy of …任由……摆布，在……的掌握中
如：They were lost at sea,at the mercy of the winds and the waves.
have no choice but to do sth.
该结构意为“别无选择的干……”
如：You have no choice but to obey me.
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