Gross Domestic Product (GDP) for Selected Years Year
Change since previous
year
2003
+2.5%
2004
+ 3.9%
2005
+ 3.2%
2006
+2.7%
2007
+ 2.0%
What is the chart tracking?
A. Economic growth over a certain period of time
B. The unemployment rate of workers
C. The value of goods imported from other countries
D. The average amount of income per person

I think it's a I am not quite sure.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.