When do people get old? When does lightning strike? When will the sun stop shining? Curious young minds finally get answers in this fun and informative book. From the authors of The Book of Why and The Book of How comes a third volume full of great answers to tough questions: When do volcanoes erupt? When do wasps sting? When are we sure we're right? When did history begin? When was Santa Claus born? When are we allowed to lie? When do we get a tooth...