许多英语学习者在不规则动词方面感到困难。

Many ___learners of English struggle with irregular verbs.

她非常害羞，所以她的日语进步不快，但她是一个非常勤奋的学习者。

She is very shy, so her Japanese didn't improve very rapidly, but she was a very industrious ___learner.

一个热心的学习者经常寻求新的挑战以扩展知识。

An avid ___learner often seeks out new challenges to expand their knowledge.