I'm choosing 'r' because it's one of the most common consonants in English. It often appears in combinations with 'e' and 'a' (like in "ear", "read", "fear", etc.). The pattern "____e_a__" might contain 'r' either before the 'e', after the 'a', or at the end of the word. Many common English words with 'ea' combinations have 'r' nearby.