Invest is a B2 level verb that actually has a couple of different meanings.
Firstly “invest” means to give money to a bank, business or buy something with the intention of making a profit from it in the future. For example, in 2021 it was very popular to invest in bitcoin and other crypto currencies.
Secondly, “invest” means to give something a lot of your time, energy or emotions. For example someone might invest a lot of time in a project for a client.
A lot of people decided to (3)…… in the company when it first started, and I bet they are glad they did as it is now worth around one hundred million dollars.
Examiner: “What would you buy if you won the lottery?”
Candidate: “First of all, I would buy a house and new car then I think I would invest a lot of money in property…”