First, the foods that could be making it hard to poop: Consider your ABCs -- or applesauce, bananas, and cereal, Dr. Morton says. Too much of any of these, especially cereal, could cause constipation in your baby; also, keep an eye on dairy products that are popular first foods for babies, such as cheese and yogurt.
There are three kinds of plate tectonic boundaries: divergent, convergent, and transform plate boundaries. This image shows the three main types of plate boundaries: divergent, convergent, and transform. Image courtesy of the U.S. Geological Survey.
Plate Movements In the 1960s, scientists developed a newtheory that combined continental drift and seafloor spreading.According to the theory of plate tectonics, Earthâs crust and partof the upper mantle are broken into sections. These sections,called plates, move on a plasticlike layer of the mantle.ECTION 3 Theory of Plate Tectonics 195 SECTION 3 Theory of Plate Tectonics 195 Causes of Plate Tectonics Many new discoveries have been made about Earthâs crustsince Wegenerâs day, but one question still remains.