Indentify a mistake in each sentence and correct it: In Australia, you mustn't to comment on person's accent

1.In Australia,you mustn't to comment on person's accent
2.In my family,children has to get permission before leaving the dinner table
3.When i came,the whole family is having dinner around a big dining table
4.Lang Lieu couldn't buy any special food while he was very poor
5.When you visit a temple in Thailand,you has to follow some important customs
6.people should wear short shorts an tank tops.This is disrespectful
7.People can wear sandals,but these have to has a strap around the back
8.People should to lower their voice inside the temple
9.Women have avoid touching monks