eager beaver 干活特别卖力的人；对工作极有热忱的人

【例句】
Don't be an eager beaver, we have plenty of time to do this job.
不要那么卖力，我们有足够的时间来做这项工作。

She's such an eager beaver. She never missed a lesson and always does her homework.
她真是个对学习充满热情的人，从不缺课，总是做作业。