Imagine you are in a jumping contest. Animals and insects can also enter this contest. But they might just leave humans in the dust! The first event is the long jump. The human athlete is Mike Powell. In 1991, he jumped nearly 30 feet, which is the world record for the long jump. That is about five times his own height. His competitor in the long-jump contest is a frog named "Rosie the Ribbiter." Rosie set the world record for frogs in 1986 by jumping more than 21 feet. Her record has never been broken by any other frog. Compared to Mike Powell, Rosie's jump is not that amazing. But wait! Rosie is only about 10 inches long when her legs are stretched to their full length. She can jump more than 25 times her size. Rosie, the frog, wins the long-jump event. The next event is the high jump. Javier Sotomayor, the world record holder, can jump a bar   8 feet high. That is about as high as the ceiling in most homes. Looking around for someone to challenge his record, Javier might need a magnifying glass  . The next _ is a tiny insect called the spittlebug  . The spittlebug can jump 28 inches into the air. It is only a quarter-inch long, less than the width of a pencil. If the spittlebug were the same size as Javier, it would be able to jump 600 feet into the air. That is like a human jumping over a building 55 stories high! Though the humans lose the "jumping contest," their competitors would probably agree that Mike and Javier are still pretty excellent athletes. If only Rosie and the spittlebug could speak! In the author's opinion, Rosie and the spittlebug's jumping abilities are   _  .
surprising promising doubtful fearful