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Chinese has been added to the graduation exam list by Sophie School, an Italian high school and 29 students will take the test this year. This high school is mainly about language in northeastern Italy. It has become the first school in the country to list Chinese as a graduation exam subject. The Chinese course has been taught at this Italian school for 5 years, and 145 of its 910 students have chosen to study Chinese. Maria, director of the school, said Chinese will become a global (全球的) language in the future and they set up the course because many students had asked for it. "There were only a few schools in Italy which provided Chinese courses then, but now, Chinese courses have become an important part of our teaching plan," she said.
Robert is a student in this school. He is going to take the Chinese test this year. He said that Speaking Chinese is not so difficult, it was difficult for them to understand the same word in different sentences and read Chinese poets, but writing Chinese characters (汉字) is the most difficult part of learning the language. "Although learning Chinese is difficult for Italian students, when considering looking for better jobs abroad, China must be my top choice," he said.
4C(g)+D(s)，达到平衡时C的浓度为w mol·L-1，若维持容器的体积和温度不变，按下列四种配比方案作为反应物，达平衡后，使C的浓度仍为w mol·L-1的配比是( )