中文回答：
通常情况下，留学一年属于长期学习，不办理签证是不可以的。几乎所有国家都要求国际学生在境内进行长期学习（超过一定期限，如 6 个月）时，必须申请专门的学生签证（Student Visa）或学习许可（Study Permit）。旅游签证或短期访问签证通常不允许从事全日制学习，且停留时间有限。具体要求需根据目标国家的移民政策确定，建议直接查阅该国驻华使领馆官网或联系学校国际事务办公室获取准确信息。
英文回答：
Generally, studying abroad for a year without a visa is not allowed. Most countries require international students engaging in long-term study (exceeding a certain period, such as 6 months) to apply for a specific student visa or study permit. Tourist visas or short-term visitor visas typically do not permit full-time study and have limited stay durations. Specific requirements depend on the immigration policies of the target country. It is recommended to check the official website of the country's embassy/consulate in China or contact the university's international office for accurate information.