...try to stay calm, assess the situation, and if possible, avoid confrontation. If there's immediate danger, I'd seek help from nearby adults or call emergency services.
...try to ignore the bully if possible, but if it persists, I would definitely tell an adult, such as a teacher or parent, about what is happening.
...stand up for my friend. I would try to de-escalate the situation by speaking calmly, and if necessary, I would seek help from an adult.
...not tolerate it. I would try to help the weaker person, perhaps by speaking to the bully directly if it felt safe, or by getting an adult's help immediately.
My actions would be:
If I were threatened, I would: defend myself (if necessary), say NO, ask for help, tell an adult as soon as possible.
If I were bullied, I could: stand up for myself, say NO, tell an adult as soon as possible, try to explain that (if appropriate), help each other.
If my friend were bullied in my presence, I would: defend someone from the bully, try to help, tell an adult as soon as possible, help each other.
If someone bullied weaker people in my presence, I would: defend someone from the bully, try to help, tell an adult as soon as possible, help each other.