Astrobiologists are concerned with finding

Which two statements are true about a system? 1. a system is a group of objects analyzed as one unit. 2. energy that moves across system boundaries is conserved. 3. there’s only one way to define the boundaries of a system. 4. all systems are made by humans.

Which is these sentences can be deleted from the first paragraph sentence 4 sentence 2 sentence 5 sentence 3

Which of the following is a characteristic of the coverdell education savings account