在设计探究实验时，下列不能作为一组对照实验的是（    ）

根据对短文的理解，选择正确答案。

    For children,healthy eating is one of the most important things. Here are some ideas about how to keep fit.

    Having breakfast

    A good breakfast is very important for children. But some children often go to school without breakfast, just because they want to sleep a little longer. Remember a good breakfast will help you study better.

    Having milk

 “My dream is that all the Chinese children can get half a kilo of milk a day.” The Chinese Premier(总理)Wen Jiabao said this during(在……期间)his visit to a milk farm.Milk is also very important to children's health. It makes children grow stronger. It's better for you to have a glass of warm milk before going to bed.That will help you have a good sleep.

    Having healthy food

Having healthy food is the most important. That is eating lots of different kinds of food,especially(尤其)fruit and vegetables.Don't eat too many sweet snacks. Some of you like eating fast food, but it is not good for your health.

下图是小梅配制100g溶质质量分数为12%的NaCl溶液的实验操作示意图：

（1）计算：需要NaCl的质量为　____ g，需要水的体积为____ mL．

（2）上图中的玻璃仪器分别是广口瓶、量筒、____ 、____ ．

（3）指出图中的一处错误操作____ ．

（4）配制时应选择　____ mL（10mL或50mL或100mL）的量筒量取所需要的水．用上述图示的序号表示配制溶液的操作顺序____  ．