Step 1: Identify the two context clues. The sentence gives two clues: "weak" and "painful". Step 2: Understand what these clues tell us about movement. Weak legs cannot support fast movement. Painful legs make each step uncomfortable and careful. Step 3: Eliminate options that describe feelings, not movement speed. "Happily" and "angrily" describe emotions. The clues describe a physical state. Step 4: Choose the word that fits both clues. "Slowly" fits because weak and painful legs would make a person take small, careful steps. Answer: slowly