20 13 During the "May Day" period, Xiaoming and Liang Xiao plan to choose a scenic spot from Dongying Port, Yellow River Estuary and Longyue Lake, and Xiaoming and Liang Xiao will pass.

Analysis of test questions: represented by A, B and C: Dongying Port, Yellow River Estuary and Longyue Lake;

Draw a tree:

∫ * * There are nine possible outcomes, so there are three situations in which two families draw the same scenic spot.

Then the probability that two families draw the same scenic spot is:.

So choose a.

Test sites: list method and tree diagram method.