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- The principal species are C. maxima and certain varieties of C. pepo. 主要的种类是笋瓜（C.;maxima）和西葫芦（C
- One of the principal species is arbor, which includes arborvitae, East-liaoning oak, China Armand pine, birch, and fir. 主要树种有侧柏、辽东栎、华山松、桦、冷杉等乔木；
- My wages are the principal source of my income. 薪金是我收入的主要来源。
- The principal shareholder ask for a meeting. 主要股东们要求召开会议。
- The agent spoke on behalf of his principal. 代理人代表他的委托人说话。
- Keys are available on application to the principal. 向校长申请就可得到钥匙。
- She's been downgraded (from principal) to deputy. 她已(从校长)降为副校长。
- Do wolves belong to the canine species? 狼是犬科动物吗？
- Our principal problem is lack of time. 我们的主要问题就是缺少时间。
- We should do our best to save endangered species. 我们应该竭尽全力挽救濒于灭绝的生物。
- She drank in every word of the principal's lecture. 她全神贯注地听校长演讲的字字句句。
- John informed the principal against Paul. 约翰向校长告发了保罗。
- The central or principal vein of a leaf. 中脉中心的或主要的叶脉
- This rare bird has become an endangered species. 这种珍禽已成为濒临灭绝的物种。
- The principal discouraged unexcused absences. 校长不准无故缺课。
- He was wearing a strange species of hat. 他戴着一种奇怪的帽子。
- Rubber is the country's principal export. 橡胶制品是该国主要的出口产品。
- The principal has a very tight schedule. 校长的日程表排得满满的。
- Our school gave a reception to our new principal. 我们学校为新校长举行了欢迎会。
- The principal knew all the students individually. 校长认识每个学生。
