The children mustn't go near the dog. It'll bite them

use the conditional sentence 1 to rewrite the following sentences
1 The children mustn't go near the dog. it'll bite them
--->
2 Philip might fail her driving test. but she can take it again
--->
3 Manchester United might lose. if they do, Tom will be upset
--->
4 The office may be closed. in that case Mark won't be able to get in
--->
5 Nick and Marta may arrive a bit early. if so, they can help Tom to get things ready
--->