当Simon走进教室时,数学老师已经开始讲课了的翻译：When Simon came into the classroom, math teacher has begun lecturing 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

When simon came into the classroom, the lecture has started a math teacher

When Simon came into the classroom, math teacher has begun lecturing

When Simon enters the classroom, mathematics teacher already started to teach

When Simon walked into classrooms, mathematics teachers have already begun teaching classes

When Simon came into the classroom, math teacher has begun lecturing