The men who guard the Queen

If you’ve ______ been to London, you’ve probably seen them: they are the soldiers in bright red jackets or shining helmets who stand outside Buckingham Palace. They are men who can stand absolutely still, even when tourists tell them jokes, touch them, push them, or try to make them move. They may look identical and even march like robots, but they are in fact some of the besttrained soldiers in the British army. Some people are surprised to learn that the guns that the soldiers carry are not just for show: they are loaded!

Fill in the blank with the appropriate word to complete the text.