Groups, usually referring to the aggregation of various social members relative to individuals, are actually a collection of people. They can be divided into formal groups, informal groups, and quasi-groups. Quasi-groups refer to people without an organizational structure. There is some kind of connection between people, there is a certain degree of common concern, and it is possible to form a group at some time, but a group that has not yet been organized. Which of the following belong to the quasi-group? ['Somewhere, a family with a large family name held a large banquet to worship their ancestors, and many people did not know each other at the banquet.', 'In a community in the network, some outdoor sports enthusiasts who have never met meet to discuss climbing in a certain place.', 'During the National Day, more than 100,000 tourists from all over the country visited the Summer Palace.', 'A certain officer and soldier saw a car encounter a mudslide during training, and quickly organized a rescue.']