David often thought of the aliens of other planets. He wished he could meet them. One night when he was fast asleep, he saw three strange creatures in his dream. They looked like big brinjals with antennae bulging out of their heads. There were spots on their faces. They spoke in a strange shrill voice. David was very afraid. He shouted for his Mom and Dad. But the aliens stopped David and told him “ Don’t be afraid. We came from another planet. We know that you always wanted to meet us. But we came all the way to tell you something.” David asked, “What is that?” “Please tell other human beings that they must keep their planet clean and green. They should not litter to make their surroundings dirty.” said one of the aliens. And the aliens disappeared. When David woke up in the morning, he couldn’t find any trace of the aliens. But David recalled what they had said.