Complete each definition by matching the sentence parts. a. alive, such as an animal, bird, or insect. b. difficult because it tests one's abilities. c. it lives or is present in a particular place. d. that you put it in a dangerous situation. e. the upper layer of something, such as water. f. to everything in space, like stars and planets. g. to use up all of it so that you have no more. 1. Something that is challenging is . 2. A creature is something that is . 3.To say something exists means . 4.If you risk something, it means . 5.To run out of something means . 6.The surface of something is . 7.The universe is the name given .