4. Dad, Mom, the guest, and I, four people, are sitting around a round table having tea. If we only consider the person on each person's left, how many different seating arrangements are there?
4. There are 6 different ways to be seated

Method
4. [Solution] The first person has 4 positions to choose from, after the first person is seated, there are three cases for the person sitting to his left, and for each case, the left neighbor of the other person has two options, so there are $4 \times 3 \times 2$ $=24$ ways. However, since it is a round table, only the adjacent situations are considered, not the specific side they are sitting on, so there are only $24 \div 4=6$ ways to be seated.