To compare the moral reasoning skills of younger and older children, Professor Hauten tested and retested a group of children from the time they were 4 until they reached the age of 12. The professor conducted a study.

longitudinal

Explanation:

Longitudinal study: In psychological research, the term "longitudinal study" is also referred as "panel study" or "longitudinal survey", and is described as a research or study design that encompasses distinct repeated observations of the same participants or variables by the researcher, investigator, or experimenter for either a long or short period in time.

In the question above, the given statement signifies that the professor conducted a longitudinal study.

they encountered severe weather for which they were poorly prepared.

permafrost layer, it exists beneath a layer of soil, rock or sediment.