Ming has been spending an hour a day over the past six months collecting discarded cardboard on the streets of Sham Shui Po. The most the 15-year-old earned in a week was HK$25 (S$4.30) for 5kg. The older child of a divorced 39-year-old cleaner, he prepares lunch for his 10-year-old sister and tutors her. "When I think of how hard.