Can you identify the root of the word 'unbelievable'?

你能识别出'unbelievable'的词根吗？

同一单元的其他句子

• The professor emphasized the core vocabulary in today's lecture.教授在今天的讲座中强调了核心词汇。
• Can you define the term 'sustainable development' accurately?你能准确定义'可持续发展'这个术语吗？
• Students must memorize the essential words for the upcoming exam.学生必须记住即将到来的考试所需的基本词汇。
• Do not overlook the importance of context when learning new words.学习新单词时不要忽视上下文的重要性。
• Please revise the key terms before the class discussion.请在课堂讨论前复习关键术语。