下列字形有两个错别字的一项是（    ）

2010年11月4日， 中国******抵达巴黎，对法国进行为期3天的国事访问。法国总统萨科齐以最高规格接待中国国家元首。下列对法国总统认识正确的是
①总统是由选民直接选举产生的                       
②总统既是国家元首又是政府首脑 
③在法国政治舞台上总统居主导地位，在国防和外交领域发挥决定性作用 
④总统有权直接任命总理，总理只对总统负责

某班 $m$ 名学生在一次考试中数学成绩的频率分布直方图如图，若在这 $m$ 名学生中，数学成绩不低于100分的人数为33，则 $m$ 等于（   ）

高纯度氧化铝有广泛的用途，某研究小组用以下流程制取高纯度氧化铝：

根据上述流程图填空：

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．