allow sb / sth to do sth:People aren’t allowed to eat food on the underground in Nanjing.在南京，地铁上禁止人们吃东西。
if we take short breaks__.19. Food in small pieces could be eaten easily from the sun twigs which_ turned into chopsticks.20. Walls make of adobe take in the heat from the sun on hot days and give out that heat_ during cool nights， thus warning the house.21. …
