Once there were two crows  whose opinions  were always opposite. One day, one of the crows said to the other, " You should realize, of course, that I can fly much higher than you." " Don't be ridiculous  ." the other crow said. " Everyone knows that I can fly much higher than you." "No, you can't" the first crow said. "Yes, I can" the second crow replied, and the argument went on and on. At last they decided to have a contest to solve the argument. " We will compete to find out who can fly higher while carrying a bag" the first crow said. They argued for some time because of the size of the bag, but at last _ . Then there was a further argument about what each bag would be filled with. Finally, they agreed that the first crow would fill his bag with cotton and the second crow would fill his with salt. The first crow thought he was clever to agree to this, because salt is much heavier than cotton. At last they were ready for the contest. Holding their bag in their mouths, they flew into the sky. They had not been flying for long. However, when it began to rain- as the second crow had expected it would. Can you guess who could fly higher? The two crows were arguing about   _
who was much clever who can fly higher how to fly into the sky how to carry the bag