1. 带兵, it means leading the troops/armies. 带兵作战 lead the troops to fight
2.父母说他还没有独立带兵作战的资格。可是,糊涂的赵王哪里听得进去。
Parents said that he still hasn't been qualified to lead the troops to fight. But, how could the silly/muddled emperor Zhao put their words into mind?
3. What does mean 心里有说不出的高兴。 this sentence In English
There is a happiness in heart which can't be told/expressed. (Here it means that he/she is too happy to express his feeling by words)