How do you use the word crucial in a sentence?

The government's ongoing operations are crucial in maintaining the wetlands.

The merger negotiations were at a crucial point.

The crucial step in the operation is restarting the patient's heart.
Her answer was crucial in finding the location of the treasure.

It is crucial that you continue taking the antibiotics until your prescription runs out, or else the infection will not be cured and you will get sick again.

Unfortunately, the DVD always skips at that crucialmoment, so I still don't know why Frankie switched sides and ratted everybody out.