сделайте предложения вопросительными и отрицательными
1.We have just sent a telegram 2.They have already seen that exhibition 3. We have known him for more than ten years 5. My friend has already left for Moscow

1) Have we just sent a telegram? We haven't just sent a telegram2) Have they already seen that exhibition? They haven't already seen that exhibition3) Have we know him for more than ten years? We haven't know him for more than ten years 5) Has my friend already left to Moscow? My friend hasn't already left for Moscow