The moral is to be a high school (dumpling) scholar.
Because it's the Dragon Boat Festival, many parents of candidates have recently added rice dumplings to their menus when preparing their college entrance exam meals. First of all, the Dragon Boat Festival to eat dumplings is traditional; secondly, "dumplings" and "in" pronunciation close, parents want to get a good luck, meaning "high school (zhònɡ)". Hangzhou, some high schools in order to motivate students, but also prepared a number of dumplings to eat dumplings activities.
Extended information:
Zongzi is the traditional food of the Dragon Boat Festival in the Greater China region, the Kansai to Hokuriku region of Japan and Vietnam. On the eve of the Dragon Boat Festival, every family has to dip the glutinous rice, wash the zongzi leaves and wrap the zongzi, and in addition to eating them at home, friends and relatives also give them to each other.
The custom of eating rice dumplings at the Dragon Boat Festival originated in the Eastern Han Dynasty of China, when people were already accustomed to eating rice dumplings with a unique aroma during the 5th of May and the summer solstice to eliminate the summer heat. In the Jingchu area, cooking glutinous rice or steamed rice dumplings into the river, to worship Qu Yuan. Later, gradually with rice wrapped in zongzi leaves instead of bamboo tubes. Now all over the zongzi regardless of shape or content, there are a variety of changes.
Baidu Encyclopedia - Dragon Boat Festival