Doctors tell us that food with _____ salt is bad for our health.
句意：医生告诉我们吃有太多盐的食物对我们的健康有害。表示“太多”，而且用来修饰不可数名词 salt 的短语是 too much，故答案为选项B。
— Excuse me,Mary. Can you read "198" in English?
— Yes,of course. _____.
根据198的读音可知答案为选项C。
According to a survey,four out of five women do housework at home,but only _____ of men would do it.
句意为：根据一项调查，五分之四的女性在家做家务，但是只有五分之二的男性会做这项工作。分数的表达方式：分子用基数词，分母用序数词，当分子数字大于一时，分母序数词后需要加 -s。故排除A、C。根据句中的 but only 可知空处应小于五分之四。故选选项D。
250 babies are born every minute in the world. That makes over 131.4 _____ births a year.
根据设空处前的具体数字131.4可知，此处要用 million 的单数形式，而且其后不加介词 of，故答案为选项B。