What are the missing letters? (nd or ld)

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
   ld      nd   
1. I hope we fi the ball.
2. The old lady was so ki to us.
3. Do you mi if I go?
4. She has a mi case of the flu.
5. The chi was running in a race.
6. The animal was wi.