caption: The image shows a group of people standing in front of a building with smoke billowing out of it. Some of the people are wearing helmets and jackets, while others are holding cameras. There are also metal objects and other items scattered on the ground. In the background, there are pillars and buildings, suggesting that the scene is taking place in a city. This image is likely related to the Hong Kong protest, as it is a reminder of the five things you didn't know about the protest.