Simple Past or Past Continuous?

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!
Yesterday, Peter (see) a strange dream. He (sit) near the river and he (read) a book when suddenly, a fish (jump) out of the water! He immediately (get) up and (catch) it. He (throw) it back into the river to save it. But it (is) a magic fish! It (swim) away, when it shouted back at Peter "Thank you, very much!". Peter was so surprised, that he (wake) up!