1. call it a day - to decide to stop working for the day.
2. go down the drain – this means when you lose or waste something.
3. go through the roof – when something increases very quickly.
4. off the top of my head – when you say something without thinking
about it for a long time or doing any research.
5. touch base - to make contact with someone. 

*Dispones de más Ejercicios de Inglés Comercial y de Negocios
con respuesta para practicar.