To "let the __________ out of the bag" means to reveal a secret by mistake. Eg: We are planning a surprise party for John this Saturday, please don't let the __________ out of the bag.

To "have a __________" means to become agitated or angry. EG: Please don't tell dad I dented the car, he'll have a __________ .

to be like "a __________ in a china shop" means to break or damage things, or make mistakes when you need to be careful. EG: My son is a bit of a __________ in a china shop so I'm worried about taking him along to the fine arts museum today.

To "look a gift __________ in the mouth" means to criticize or find fault with something that was given to you for free. EG: My dad gave me his old dented car as my 18th birthday present, but I guess I shouldn't look a gift __________ in the mouth, right?

To "be in the __________ house" means to be in a bad situation because someone is angry at you. EG: I forgot it was my wife's birthday yesterday so I'm in the __________ house again.

To be "on a __________ expedition" means trying to find information, especially damaging information by asking random questions. This is often done without knowing what information will be revealed by the questions.

To be "a sitting __________ " means to be in a situation with no protection, that is easy to attack or take advantage of. EG: Without the latest anti-virus software your computer is a sitting __________ for any would-be hackers.

The " __________ in the room" refers to an obvious or major problem that everyone tries to ignore or avoid. EG: When the family attended my brother's 18th birthday party, everyone tried to avoid the __________ in the room. They knew he had failed his final high school year exam.   

To be "a paper __________" means to appear to be threatening or powerful from an outside view but to really be ineffectual or weak. EG: The school bully was revealed to be nothing more than a paper __________ when the new kid stood up to him and refused to hand over his lunch yesterday.

"Like a __________ in the headlights" means to be so frightened or surprised that you cannot move or think. EG: The new stand-up comedian was like a __________ in the headlights when he walked on stage and saw the huge audience.