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

Which lists the main components of darwin’s theory of evolution? a. random mutations drive evolution; the evolution of a population happens slowly; organisms have common ancestors; organisms do not change. b. natural selection drives evolution; the evolution of a population happens slowly; organisms have common ancestors; organisms change over time. c. natural selection drives evolution; the evolution of a population happens rapidly; organisms have common ancestors; organisms change over time. d. random mutations drive evolution; the evolution of a population happens rapidly; organisms have common ancestors; organisms do not change.

Which of the following is not a means to accelerating? question 4 options: a)increase speed b)remain still c)decrease speed d)change direction

Isobars are lines of constant or equal pressure on a weather map. they can be used to find areas of low or high pressure over a broad area, and they can tell us how intense the system may be. on weather maps, you may have noticed areas that have a large l or h over a region with lines circling around them. the l stands for low pressure and h stands for high pressure. the lines circling them are isobars. check out the pressure system and isobars over georgia and florida. what is the present weather in this area ? a) clear and sunny b) cold and cloudy c) changing weather d) lots of precipitation