我想请问听力第二部分的第1和第3题
1. What do the speakers mainly discuss?
答案(2个): Whether a focus on wood harvesting is an appropriate topic for
the man's paper.
Why the man became interested in wood harvesting techniques.
为什么不能选: How the man should narrow the focus of his paper.
后来The man不是有跟professor说要写Native Americans in this area吗?
3. What had the man assumed about human impact on the environment?
答案: That human impact on the environment is always harmful.
为什么不能选:That humans have only recently had an impact on the environment.
谢谢各位！