三个语法问题～

1. Employers who do credit checks operate under the assumption that having had trouble paying bills is a character flaw, but there is scant hard evidence to back this up. 老师，这个“had”不需要去掉嘛？直接说"…under the assumption that having trouble paying…"不可以嘛？还有这个scant在形容词hard之前，不需要变副词scantly嘛？2. The use of credit checks is growing at a time when the economy is making it hard for people to keep their records cleanly. 老师，"making it hard for people…"能去掉it嘛？

1 having had trouble paying bills is a character flaw 这个分句中，having had trouble paying bills是动名词完成体作主语，表示动名词的动作是先于谓语时间的过去的动作。改为动名词一般体having touble paying bills 则有歧义，由于动名词的一般体doing形式既能够表示先于谓语时间的动作，也可以表示 与谓语时间同时的动作。这个句子是关于信誉核查的，一个人的信誉涉及既往的状况，所以最好使动名词的完成体，明确该动作是先于谓语时间的过去动作，防止歧义。

2 scant并非修饰hard, 而是修饰hard evidence这个名词词组，所以不可用副词，要用形容词。

3 make it hard for sb to do sth. it是形式主语，不定式复合结构为外置宾语（真的宾语），hard是宾补。形式宾语it不可省略！