Cheers to my friends thats skyline west snug cheers my friends

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 of the following must happen in order for productivity to increase? a. production levels remain unchanged while inputs increase. b. production levels rise while inputs decrease. c. production levels fall while inputs increase.

How should the syntax in this sentence be changed, if at all? the scientists spent years analyzing the results of numerous medical studies meant to identify the cause of the disease. no change the scientists spent years looking at the results of a variety of different medical studies meant to locate the cause of the disease. the scientists spent years reviewing medical study results to find the cause of the disease. the scientists spent years studying the results of many medical studies in order to uncover the cause of the disease.