改错题。 1. They had three major concerts and made a hit CD in the last six months. 2. Only a few people said they have seen them in the concert. 3. If the weather is fine, they won't go to the park next Sunday. 4. I have not seen this film already and I am going to see it next Sunday. 5. Have you ever sang in front of other people? ______ ______ ______ ______ ______