若$a$为常数，且$a>1$，$0\le x\le 2\mathrm{\pi }$，则函数$f\left(x\right)={\cos }^{2}x+2a\sin x-1$的最大值为（  ）

根据以下五位学生在英语学习中遇到的困难，从所给的选项A-E中，选出每个人所需要读的文章。

①Gamaham: The most difficult thing about learning English is to remember new words. I study the words and remember them, but a week later I have forgotten most of them. When reading something in English, I always get into trouble when I come across a new word. There must be a better way to learn new words. ____ 

②Viekers: I have been studying English for so long now, and I don't enjoy it any more. I used to like it, but now I feel as if I'm not making any progress. I wish there was something I could do to make me interested in studying English again.  ____ 

③Selina: I wish I could improve my spoken English. Every time I join in a group discussion or try to speak English to someone, I find it difficult to express myself. I don't know what to say and I can't think of the words I need. ____ 

④Gina: I don't like English at all. Why do we have to study English? I'd rather spend more time on maths and science, because I think those subjects are more important. ____ 

⑤Jim: I think it's easy to remember new grammar rules, but when writing something I always make a lot of mistakes. How can I learn to use the rules that I have learned? ____ 

下图所示的线路促进了中外经济文化的交流，为这条线路的开辟作出重大贡献的历史人物首推(     )