input: Write a function to store the strings "Hello" and "World" in two separate variables and print them on the same line, separated by a space. Define the variables as string1 and string2, assign the appropriate values, and use the print function to output the combined string.
  
  assert print_hello_world(string1="Hello", string2="World") == "Hello World"
output: def print_hello_world(string1, string2):
      print(string1 + " " + string2)