Preparing for a visit to a foreign country can often be overwhelming, with no shortage of things to learn before you go. Where should you eat? Where should you stay? What do you tip? More so than this service information, though, is a sense of cultural understanding that’s hard to put your finger on. With this in mind, language learning app Babbel asked foreign ambassadors to the U.S. to pick the book they believe first-time visitors to their country should read before they arrive. Their answers may surprise you.