1.put hair on your chest
、、、、、、make you strong and health.
2.a (royal）pain in the neck
、、、、、、someone who is very annoying and always disturbing.
3.a long shot
、、、、、、a risk bet,an attempt at or a proposition that has a low probability of success.
4.my best shot
、、、、、、to do something as well as you can ,althoug you are not sure whether you will be able to succeed.