1. ) remember to say sorry when you have done something wrong 
2. -> don't ........forget to ........say sorry when you have done something wrong ........
3. 2) despite the difficult math question , Vicky solved it in five minutes 
4. -> although the math ......question so difficult,..Vicky solved it in five minutes ..........

2, Don’t forget to say sorry when you have done something wrong.

3, Although the math question was difficult, Vicky solved it in five minutes.

4, I have such a humorous friend that I can’t help laughing at their jokes.

5, If Bill drove carefully, he would not have many accidents.