Can you add two strings? What effect does ' + ' have on strings?

What is the result of the following expression?

print("""
1
 2
  3
""")

What is the result of the following expression?

print ('One', ' Two ' * 2)
print ('One ' + 'Two' * 2)
print (len('10123456789'))

What is the result of the following expression?

s = '0123456789'
print(s[3], ", ", s[0 : 3], " - ", s[2 : 5])
print(s[:3], " - ", s[3:], ", ", s[3:100])
print(s[20:], s[2:1], s[1:1])