It records your progress help you see what you have achieved

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.

According to the passage weisers mother could be blamed for

Balanced rock sits on a thin spike of rock in a canyon what forces keep the rock balanced on its tiny pedestal