Throughout the week, the weather was very bad. The sun finally came out on Sunday. Mark and Amy decided to go for a walk in the countryside and enjoy the splendid sunshine. They took the bus to Sai Kung. Along the way, the bus stopped to let them off near the entrance of the country park.

The bus travelled on and met with an accident. Last week’s heavy rain had loosen the earth on a slope causing a landslide. A huge rock rolled down the slope and landed right on the bus. The bus was crushed! Many passengers suffered severe injuries. Two of them died.

How lucky! If we had not got off the bus, we would have died. Oh, my goodness! If we had stayed on the bus, …….

Think about the condition and the results. If the couple had stayed on the bus, would it have stopped? If the bus had not stopped, would it have reached the spot of the accident earlier or later? If the bus had reached the spot earlier or later, would the rock have landed on top of the bus? If the rock had not landed on the bus, would people have died? Would the accident have happened if the couple had stayed on the bus?