一 Why do English people talk so often about the weather when they start a conversation? 一 Well, it’s probably because the weather is a(n) _____ topic. [ ]

You have failed to do what you toand I’m afraid the teacher will blame you．

What shocked the world was the fact _____challenger crashed just minutes after take-off. [ ]

What’s that– _____ a key.

The rain had cleared the air, and the grass ______ fresh and sweet.