Correct these wrong sentences

1 It is dad's birthday today.
2 Mike and Ted are making soup to surprise their mum.
3 They are making Whities
4 Their cake looks like an old boot
5 Mum thinks this is terrible surprise.
6 Mike and Ted must clean the bathroom before the guests arrive.

1 It is dad's birthday today. - ok2 Mike and Ted are making soup to surprise their mum. - ok3 They are making Whities  - не понимаю, но кажись всё ок - в тему4 Their cake looks like an old boot - ок5 Mum thinks this is a terrible surprise. - ок6 Mike and Ted must clean the bathroom before the guests arrive.- окто есть грамматически все ок. может с фактами что-то не так?