题目

阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项。 Word came that a 13-year-old girl fell intoa sewer(下水道) and was rescued. The girl, Alice, was 1for more than12 hours in the city's 2undergroundsewage system. It was filled with waste liquids and other waste materials 3 a adisgusting smell, which was 4. Alice had been playing at a public park withother kids during a family 5on Sunday. Atone point, the children were on pieces of wood that 6 an opening leading to the sewage system. Oneof the wooden boards 7sudd在一个大萝卜中间挖一个大孔，向其中注入饱和食盐水，过一段时间，将孔中的食盐水倒出，向倒出的食盐水中加足量的NaCl(设温度不变)，则食盐水的质量 [　　] A．减小 B．增大 C．不变 D．无法判断