for the applicant to locate includes such items as the location of the home and regional offices，the financial status of the company，plans for expansion，and company philosophy.information about most major corporations is available in reference books and periodicals.
上段第一句是段落的主题句，句子的大意是：申请工作的人在接受面试前有责任了解某些方面的信息。主题句中的关键词是ascertaining certain types of information.紧接着，文章围绕主题句从两方面展开，论述了申请人应了解两类信息。
if europeans thought a drought was something that happened only in africa，they know better now. after four years of belownormal rainfall （in some cases only 10 percent of the annual average）， vast areas of france，spain，portugal，belgium，britain and ireland are dry and barren 。water is so low in the canals of northern france that waterway traffic is forbidden except on weekends.oyster growers in britain report a 30 percent drop in production because of the loss of fresh water in local rivers necessary for oyster breeding.in southeastern england，the rolling green hills of kent have turned so brown that officials have been weighing plans to pipe in water from wales.in portugal，farmers in the southern alentejo region have held prayer meetings for rain-so far，in vain.
上段中第二句是主题句，它点明了全段的中心思想，即：四年来，法国、西班牙、葡萄牙、比利时，英国及爱尔兰的降雨量低于常年，这些国家的广大地区都严重缺水。下面的各句都是围绕这一主题展开的。
从上面两段中我们可以看到英语的段落只能有一个中心思想，如要再论述其他与该段中心思想无关的内容应另起一段。
2.主题句的位置
主题句的位置可以在段首：
london‘s weather is very strange 。it can rain several times a day；each time the rain may come suddenly after the sun is shining brightly.the air is damp（潮湿的）and chill（冷的）right through july.on one march afternoon on hampton heath last year it rained three times，there was one hail（冰雹）storm，and the sun shone brilliantly-all this within two hours’s time.it is not unusual to see men and women rushing down the street on a sunny morning with umbrellas on their arms.no one knows what the next few moments will bring.
主题句的位置可以在段落中间：
just as i settle down to read or watch television，he demands that i play with him.if i get a telephone call，he screams in the background or knocks something over.i always have to hang up to find out what‘s wrong with him， babysitting with my little brother is no fun. he refuses to let me eat a snack（快餐）in peace.usually he wants half of whatever i have to eat.then，when he finaly grows tired，it takes about an hour for him to |
