The plan is rock-solid and will work perfectly.
Very strong and reliable; not likely to change or fail.
The foundation of the building is rock-solid.
Extremely stable or secure; not easily moved or affected.
He is a rock-solid friend who always helps me.
A person or thing that is very dependable or trustworthy.
He has a rock-solid plan for the project.
Very strong or solid.
So silným bezplatným obrázkovým slovníkom a kartičkami.
