1.(To) be in one's element:
Def: To be completely comfortable doing something; To do something that comes very naturally to someone
ex. "When it comes to speaking in public, the Senator is in his element."
2.Behind (someone)
Def: In the past.
ex: "I used to smoke, drink, and take drugs, but all that is behind me now."
3. (To have a) big mouth:
Def: To not be able to keep a secret.
ex: "Don't tell her anything. She's got a really big mouth."
4. (To) blow someone's cover:
Def: To reveal someone's secret, or true identity.
ex. "The spy was very careful not to blow her cover."
5.(To) break new ground:
Def: To do something that hasn't been done before. To innovate
ex. "Dr. Davis was breaking new ground in cancer research."
