Complete each definition by matching the sentence parts.【请直接填写对应的小写字母】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 ischallengingis ____________.2. Acreatureis something that is ____________.3. To say somethingexistsmeans ____________.4. If yourisksomething, it means ____________.5. Torun outof something means ____________.6. Thesurfaceof something is ____________.7. Theuniverseis the name given ____________.