The idiom "take it or leave it" means that you have two options: you can either accept something as it is or reject it completely. It's usually used when someone is offering you something, and they're not willing to negotiate or change the terms of the offer.
For example, imagine you're buying a used car from someone, and they tell you the price is $5,000. If you ask them if they can lower the price, and they say "take it or leave it," they mean that the price is non-negotiable. You can either buy the car for $5,000 or not buy it at all.
Another example could be if your friend invites you to go to a party, but you don't like the idea of going. If they say "take it or leave it," they mean that you can either go to the party with them or stay home, but they're not going to change their plans or try to convince you to come.
Overall, "take it or leave it" is a straightforward way of saying that there are no other options or compromises available.
• The book publisher is offering you a contract with some terms, take it or leave it.
• We have a strict deadline for the project, take it or leave it.
• The company is offering you a promotion with some conditions, take it or leave it.
• The government has proposed a new policy, take it or leave it.
• The restaurant has a fixed menu for the day, take it or leave it.
• I can only offer you $10 for this old book, take it or leave it.