氟试剂分光光度适用于测定含氟（）的水样，当取样体积为25ml、使用光程为30mm比色皿时，氟试剂法的检测范围是（）mg/l

翻译句子

1. She made several perchases in the dress shop. 

2. They've just perchased a new house in the country.

3. If' you are not satisfied with your purchase, you will get a full refund.