<span>Testing for intelligence at multiple ages at one point in time is cross-sectional research. The goal of this type of research is to provide data on the whole population under study. This type of study is less costly than other forms of study.</span>
Answer:
Brainly is a homework app not for cheating in the test. And really some people post about their personal lives. I just don't understand.
Your answer is D.
Hope this helps !!
Definition:
U-shaped valleys form through glacial erosion. Glaciation develops in established v-shaped river valleys where the ice erodes the surrounding rocks to create a “U” shaped valley with a flat bottom and steep sides. Glacier movement is driven by gravity. When the glacier melts, the landscape is transformed and the U-shaped valleys are clearly visible.