属于费力杠杆的是（　 　）

把AlCl₃溶液蒸干灼烧，最后得到的固体产物是                  

如图，西安路与南京路平行，并且与八一街垂直，曙光路与环城路垂直．如果小明站在南京路与八一街的交叉口，准备去书店，按图中的街道行走，最近的路程约为（　　）

我们伟大的祖国，地理位置优越，国土辽阔，人口众多。读图并结合已学的地理知识，回答下列问题。

阅读理解
    Different weather makes people feel different．It influences health，intelligence and feelings．
    In August，it is very hot and wet in the south the US．People there have heart trouble and other kinds of health problems during this month．In the Northeast and the Middle West，it is very hot in the summer and very cold in the winter．People in these states have more heart trouble after the weather changes in February or March．
    The weather can also influence intelligence ． For example，in a 1983report by scientists，IQ(智商)of a group of students was very high when a very strong wind came, but after the strong wind,
    Their IQ was 10% lower than before. The wind can help people have higher intelligence. However,very hot weather can make it lower. Students in many schools of the US often get worse in exams(考试)in the hot months of the year(July and August).
    Weather also has a strong influence on people's feelings．Winter may be a bad time for thin people．They usually feel cold during these months．They might feel unhappy during cold weather．But fat people may have a hard time in hot summer．At about 18℃people become stronger．Low air pressure may make people forgetful．People leave more bags on buses and in shops on low-pressure days．
    Are you feeling sad，tired，forgetful，or unhappy today？It may be the weather's problem．