I've got two levels, once you choose one and complete it, you will get a question 'Choose another level', but after I press the second level, it stops. I need some advice on how to keep it running. Please help! Thank you!
You don't have code to go back to the beginning, so that second choice gets interpreted as Python. Neither
b are valid Python code, so that's why you're getting an error.
To make your code go back to the beginning, put your whole program in a
while True: score = 0 print ("Welcome to THE quiz!") # ...