.设三次函数的导函数为，函数的图象的一部分如图所示，则正确的是

A：的极大值为，极小值为

B：的极大值为，极小值为

C：的极大值为

     Perhaps it takes about seven years for one to become a good English speaker. Ogden believed that Basic English could be learned in seven weeks. There were only 850 words and the grammar was very simple.

     The language attracted the attention of educators all over the world, but its development was stopped by the Second World War. After the war, both the British Prime Minister Winston Churchill and the President of the United States Franklin D. Roosevelt looked for ideas that might bring world peace. They both gave speeches that encouraged the use of Ogden's international language. In the past 60 years, the language has had some success. In some parts of East Asia, teachers are still using Ogden's word lists.

     However, in the main, the language has disappeared. Because there are many more non-native than native speakers of English, recently some linguists have asked whether we should give careful consideration to Ogden's ideas again. And the Wikipedia website (www.wikipedia.org) has started a version (版本) written in Basic English for non-native learners of the language. Search for it on the Internet now!