4. Read the text again. Then answer the questions. 1 What things cause mountains to change? and 2 What do destructive waves carry? and 3 What happens to the materials produced by the destructive waves? 4. Do constructive waves carry material a long way? 5 What do constructive waves help to make? and 6 Which type of rock erodes faster, soft or hard rock? 7 Where do you often find headlands or bays?