1. Why is 250 million years called a cosmic year? a. That’s the amount of time it takes the solar system to rotate on its axis.
b. That’s the amount of time it takes the Milky Way to revolve around the Universe core.
c. That’s the amount of time it takes the Milky Way to rotate on its axis.
d. That’s the amount of time it takes the solar system to revolve around the Milky way core.
2. Why are comets icy bodies?
a. They cluster in streams.
b. They orbit the Sun between Mars and Jupiter.
c. They lose heat as they fall through Earth’s atmosphere.
d. They originate in areas beyond Neptune

Laboratory experiments, observational field studies, and model-building are all examples of different forms of scientific investigations.  in what way do laboratory experiments primarily differ from other forms of scientific investigations?   a.  a laboratory experiment is the only accepted form of investigation within the scientific community.  b.  studies about how things behave in nature or studies involving very large objects are best answered through laboratory experiments.  c.  laboratory experiments involve the identification and control of variables.  d.  data can only be generated through laboratory experiments, not other forms of investigation.

Avehicle has an oil leak that is causing the entire oil pan to be wet, but inspection reveals no exact source after cleaning off the oil residue. technician a says to install a fluorescent dye in the crankcase and operate the engine, then re-inspect for leaks with a special light (black light). technician b says the oil leak may be coming from a source at the top of the engine, such as a valve cover gasket. who is correct?

When you jump from an elevated position you usually bend your knees upon reaching the ground. by doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. in this way the average force your body experiences is a) less than 1/10 as great. b) more than 1/10 as great. c) about 1/10 as great. d) about 10 times as great.