A world of heartbreak washes through “Questions Without Answers: The World in Pictures by the Photographers of VII” (Phaidon). Members of the pioneering photo collective bring us images, most of which were taken over the past 20 years, from wars and natural disasters, but some of which also offer a measure of hope. You see it in the faces of earnest schoolchildren in Gaza navigating around ruined buildings in search of a new classroom. It’s easy online to click through photographs from around the world, but it is something else to hold a book bigger than a laptop and linger over pictures composed by masters.