10月1日以后，太阳直射点逐渐接近的地方是 （      ）

一座长方体花岗岩石碑，质量为4.2×10³kg，底面积为0.5m²（g取10N/kg）.求：

These simple ways can increase(增加)your popularity and win you more friends，so why not try them?
●PAYING ATTENTION TO OTHERS This will reduce any shyness you may have. You’ll be more relaxed and therefore more natural and fun. And you will get more good-people will love the fact that you’re paying attention to them while you don’t have to worry about what people think of you.
●LOOKING PEOPLE IN THE EYE Making eye contact is very important because it shows you’re interested in them. If you let your eyes wander(游移)or keep looking over their shoulders，people will feel slighted(轻视)，and they’ll like you less they would otherwise.
●ASKING QUESTIONS Doing this gives you two advantages，It shows other people that you are indeed paying attention to and that you consider what they are telling you important. Being sure to follow up when you’ve shared a conversation with someone about something important in his / her life，be sure to ask about it later. This shows that you listen and you care.
●MAKING AN EFFORT TO SMILE A smile means acceptance，and that makes people open up to you. Make a conscious(有意识的)effort(努力)one day to smile at the people you stay or work with and watch how well they respond (作出反应)to you；
●BEING RELIABLE(可靠的)People like those who help them，and they quickly begin to hate those who don’t.

①明矾的化学式为KAl（SO₄）_m•12H₂O，其中m=____．

②操作①的名称是____，该操作中用到的玻璃仪器有玻璃棒、烧杯和____．其中玻璃棒的作用是____．

③操作②向液体C中加入活性炭，利用其具有____性，除去水样中的色素和异味，该过程属于____（填“物理”或“化学”）变化．

④小刚取少量液体D于试管中，加入少量肥皂水，振荡，发现有较多浮渣，说明液体D____填“硬水”或“软水”），经过操作③以后，小刚重复上述实验，他观察到的实验现象是____．生活中可通过的____方法降低水的硬度．

⑤澄清石灰水常用来检验二氧化碳气体，其机理是其主要成分氢氧化钙能吸收二氧化碳，生成碳酸钙沉淀，同时生成水．请写出该反应的符号表达式：____．