1. Dan couldn't work because he caught the flu. down
→ Dan came down with the flu, which meant he couldn't work.
2. Is it true that getting wet can cause a cold? on
→ Is it true that getting wet can bring on a cold?
3. The flu epidemic started suddenly in June and lots of people got ill. out
→ Lots of people got ill when the flu epidemic setting out.
4. I think the medicine is beginning to stop being effective. wear
→ I think the medicine is beginning to wear off.
5. It was so hot in the stadium that a number of people suddenly became unconscious. passed
→ It was so hot in the stadium that a number of people suddenly passed out.