I will stand by and watch.

I will stand by and watch the situation unfold.

I need to burn off some calories after eating all that cake.

He needs to tone down his criticism.

You can make a walk-in appointment at the clinic.

The president's speech set in motion a series of events that changed the course of history.

He acted irrationally during the meeting.

A person with a high fever may act irrationally, for example, by speaking to people who are not actually present.

The doctor diagnosed the patient with meningococcal disease.

The business tycoon built a fortune through his successful investments.