Ⅰ.单句语法填空
1．(2018·全国卷Ⅰ)Two of the authors of the review also made a study published in 2014 that showed a mere five to 10 minutes a day of running reduced the risk of heart disease and early deaths from all causes (cause)．
解析：此处的cause是可数名词，表示“原因”。根据其前的all可知，应该使用复数形式，故填causes。
2．(2018·浙江卷)Making Chinese dishes (dish) is seen as especially troublesome.
解析：此处dish是可数名词，其前无限定词，故用其复数形式泛指中国菜。
3．(2017·全国卷Ⅰ)This trend, which was started by the medical community (医学界) as a method of fighting heart disease, has had some unintended side effects (effect) such as overweight and heart disease—the very thing the medical community was trying to fight.
解析：根据空格前面的some以及空格后面列举的两个例子“overweight and heart disease”可知，应用effect的复数形式。
4．(2017·全国卷Ⅱ)In 1863 the first underground passenger railway in the world opened in London.It ran for just under seven kilometers and allowed people to avoid terrible crowds (crowd) on the roads above as they travelled to and from work.
解析：根据空格前面的形容词terrible可知此处填名词，crowd表示“人群”，是可数名词，前面没有限定词，所以用名词的复数形式。
