The Pearson product-moment correlation is an index of what type of relationship between two variables?

In time-series designs, what are the two major potential confounding factors that are difficult to control without the addition of a comparison group?

A) instrumentation and history B) regression to the mean and instrumentation C) history and attrition D) instrumentation and selection

Answer the following statement(s) true (T) or false (F)

1. Germany has some of the dirtiest air in the world. 2. Burkina Faso has successfully reclaimed land from the Sahara Desert by creating structures that funnel rainwater underground and protect the surface from the full heat of the sun. 3. Germany’s carbon emissions fell steadily between 1990 and 2016. 4. The more affluent a state is, the better a job it does of protecting its environment. 5. Ordinary citizens and non-governmental organizations have been playing an essential role in publicizing environmental challenges and advocating for changes since the nineteenth century.