Question

I've heard she's really tough.

Yeah, I'm really bummed that I have to get up so early! I'm also bummed out that Dr. Johnson is teaching this class. I've heard she's really tough.这句话中最后一个she代表是谁，是teacher还是代表那课。tough怎么解释，

Answer 1

she是指Dr. Johnson
tough意思有坚强的、强硬的意思，词句里可以隐身理解为严厉的、苛刻的、严格的。
全句解释为：起这么早我也很不愉快。更不愉快的是Dr. Johnson要教这门课，听说她严格。

Answer 2

she指的是Dr.Johnson ，tough应该是性格强硬不好相处的意思吧

Answer 3

she 说的是那老师
听说她很难缠