課題
?topic (or question) for study or discussion
?problem; task; challenge
這么多的國家如何才能做到友好合作、和睦相處，是歷史向我們提出的重大～。An important historical question is:how can these countries conduct friendly cooperation and live in harmony?/和平與發(fā)展是當(dāng)前世界的兩大～。Peace and development are two major issues in the world today./提出新的～pose a new problem;set a new task/研究～research topic