题干

如图是一个由5张纸片拼成的平行四边形,相邻纸片之间互不重叠也无缝隙,其中两张等腰直角三角形纸片的面积都为S1,另两张直角三角形纸片的面积都为S2,中间一张正方形纸片的面积为S3,则这个平行四边形的面积一定可以表示为(   )

A:4S1

B:4S2

C:4S2+S3

D:3S1+4S3

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A

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    Canada is one of the few nations in the world to have two official languages:English and French. There are 10 provinces in the country but only one of these—Quebec is known as "French Canada". This is because it was founded by French explorers while British adventurers discovered the rest.

    Canada left the Britain in 1867 to become an independent country, and English and French have been recognized as the official languages ever since.

    Most people speak English as their first language and the two national television networks broadcast in English throughout the country. Apart from in Quebec and a few places on the east coast, French television is very rare.

    The same goes for traffic signs and menus, for example. Outside of Quebec, there are only a few places where you'll see traffic signs in French. In restaurants, it's almost impossible to find French on the menu unless you are in the heartland of French Canada. However, all products sold in Canada must, by law, have labels(标签)and instructions in both languages.

    In Canada's English speaking provinces, official bilingualism(双语)means that students can choose to complete a special French language course. Under this programme, they are taught most of their subjects in French. If a student begins the course in kindergarten(幼儿园)or Grade One, it is likely that all their lessons will be in French. However, if they start at junior high school, 25 per cent of the teaching will continue to be in English.