When you see someone you have a crush on and your heart pounds, your hands get sweaty, and your cheeks feel hot, your is/are active?

Salutations!

When you see someone you have a crush on and your heart pounds, your hands get sweaty, and your cheeks feel hot, your is/are active.

When you see someone you have a crush on and your heart pounds, your hands get sweaty, and your cheeks feel hot, your autonomic nervous system is/are active

Hope I helped!

You did not show us the image of the burger, but i shall try to answer as best i can.  when purchasing food, always consider the ingredients as well as the person who prepared it. consider if they were hygienic people or not, in case the burger was infected with bacteria. no mortal should place an infected burger into their mouth.