S 1 : One of the most dangerous insect pests is the locust. P: At first they look just like ordinary grasshoppers, which are harmless and unable to fly very far. Q: Until about thirty years ago, no one knew where locusts came from or why they appeared in the different countries they attacked. R: Then they change in appearance and develop wings which enable them to fly long distance. S: Then it was discovered that there are two stages in the life of locusts. S 6 : At this stage, they gather in huge numbers and rise from the ground on theri powerful wings in cloud. The Proper sequence should be: