Some COOL riddles!!!!!!!!!!!

Here are some riddles that i found interesting!try answering them if u think you can do!!

1.Some months have 30 days & some months have 31 days. How many months have 28 days?
2.What is so unusual about the number 2520?
3.What 5 letter word can have its last 4 letters removed & still sound the same?
4.From a word of 5 letters, take 2 letters & have 1.
5.There's an electric train travelling south. The wind is from the north. In which direction would the smoke from the train be blowing?
6.There is a common English word that is nine letters long. Each time you remove a letter from it, it still remains an English word - from nine letters right down to a single letter. What is the original word, and what are the words that it becomes after removing one letter at a time?
7.A woman shoots her husband.Then she holds him under water for over 5 minutes.Finally, she hangs him.But 5 minutes later they both go out together and enjoy a wonderful dinner together.
How can this be?