Which of the following principles of experimental design ensures that the explanatory variable, and not some variable over which the experimenter has no control, is causing observed changes in the response variable?

The most remarkable thing about life in the trenches is the incredible number of rats. the whole area is infested with them. no matter what you did, you can't keep them out. they get incredibly fat on all the food they steal from us. they are revolting to look at - some are the size of cats. background information: this is a journal entry from a soldier fighting on the western front. which statement best describes how this soldier felt about the trench rats? a.) he was disgusted by them. b.) he thought they were . c.) he thought they were annoying. d.) he thought they were cute.

What role and side did italy fight on during world war 1? why did they change sides? write this in your own words.

How has urban renewal affected poorer neighborhoods in major cities? check all that apply. 1. communities have been transformed to meet the needs of the modern population. 2. old stores and factories have been renovated and used for new purposes. 3. crime rates have increased as more money has come into the neighborhoods. 4. many community businesses have gone into decline or been forced to close. 5. a number of african americans have been displaced from their homes.