Complete the last example:
Example 1: The topic of ‘When the spaceship landed on Mars, the whole humanity was excited’ is space\n
Example 2: The topic of ‘I am trying to cook tofu with tomatoes.’ is cooking\n
Example 3: The topic of ‘I am writing a program on my PC’ is programming\n
Example 4: The topic of ‘I am dancing in the disco’ is