1．
Mum(putting on her coat) : I’m going to have to go down to the shop for more bread.
Alan: Why?
Mum: I’m not sure what (1) ．(happen). I made some sandwiches earlier and left them on the table (2) ．I went to answer the phone. But someone must have taken them because they are (3) ．(go).
Alan: Oh, it must have been Dad. I’m sure he was in the kitchen (4) ．(early).
Mum: No, he went off to his tennis match before I finished (5) ． (make) them, so he couldn’t have done it. (6) ．, he couldn’t carry a plate of sandwiches as well as all his tennis stuff, so I’m sure (7) ．wasn’t him.
Alan(opening fridge door): Well, it wasn’t me. But Mum, look! Are these your sandwiches here on the bottom shelf of (8) ． fridge?
Mum: Are they there? Oh, my goodness. I (9) ．have put them in there when the phone rang. Oh, dear. I really must be losing my (10) ． . Now, why did I put on my coat?