If someone has to an action or policy, they are responsible for it, and may be required to explain it to other people or be punished if it fails.
In 1938, Hitler _________ war against Poland, which started the Second World War.
A serious earthquake struck the village, __________ many people homeless.
The old woman _____ her sons and daughters _______ and see her soon.
The pretty girl is always busy helping her mother with the housework _________ I go to visit her family.
______ more effectively in the future, many people equip themselves with further education.