这两天开始试着用knitr来写点文档，碰到个小问题。
`{r just_for_try, tidy=TRUE}
cat('this is a very longlonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglong character')
`
当字符串很长时（如上），输出的html文档中，字符串会超出文本框。
有没有option可以控制？
谢谢
