已知函数$y=\sin \left(wx+\frac{\mathrm{\pi }}{3}\right)\left(w>0\right)$在$\frac{\mathrm{\pi }}{4},\frac{\mathrm{\pi }}{2}$上单调递减，则w的取值范围(     )

增加： 在缺词处加一个漏字符号（/\）, 并在其下面写出该加的词。

删除： 把多余的词用（\）划掉。

修改： 在错的词下划一横线, 并在该词下面写出修改的词。

注意：1. 每处错误及其修改均仅限一词；2. 只允许修改10处, 多者（从第11处起）不计分。

    Dear the teachers and schoolmates, it's a great honor for me to be here today and share my experiences of learning English with you. I want to learn English good to take good job, so I learn English in some difference ways. In class, I learn new words, useful expressions and grammar and take efforts to understand the texts under the help of our English teacher. After class, you do a lot of exercises prepare for the college entrance examination. I also read news and watch videos on the Internet and from other source. I have a lot of fun especial when learning English with cartoon movies.