independent clause 和 dependent clause

问题描述:

independent clause 和 dependent clause
Although Jerzy had taken several courses in computer science,he couldn't solve the problems with his hard drive.
The crowd began to clap and cheer as the team entered through a cloud of smoke.
Ernesto wanted to spend the night studying,but his wife had other ideas.
为什么前两句 Although引导的句子和 as 引导的句子属于subordinate clause.
而最后一句,but引导的句子却属于independent clause?

subordinate clause 的意思是从句,即在一个句子中属于从属的部分,而不是句子的主干结构.我们看这三个句子,第一个:Although Jerzy had taken several courses in computer science,he couldn't solve the problems w...