![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
Add commas where necessary. Change the relative pronoun to "that" if possible.
1. This is a photo of my hometown which lies along the coast
2. A river which is polluted is not safe for swimming.
3. The mekong river which flows through the south of the country is a great source of seafood.
1. This is a photo of my hometown which lies along the coast
2. A river which is polluted is not safe for swimming.
3. The mekong river which flows through the south of the country is a great source of seafood.