----- Nội dung dịch tự động từ ảnh ----- Exercise 3: Change the following sentences into negative and interrogative sentences. 1. Your sister was finishing in the lake while I was building a fire. 2. He was learning how to windsurf yesterday at eleven o'clock. 3. It was snowing there. The kids are playing and building snowmen. 4. They were playing a game when you arrived. 5. She was cooking when I came yesterday. 2012
