In human development, the nervous system develops from which germ layer?

It has been shown that even in preliterate societies, parents tend to naturally use childdirected speech, which involves responding to infants with ______ and ______

Fill in the blank with correct word

In order for a diagnosis of Alzheimer's disease to be definitively made __________.

A. brain tissue must be examined upon autopsy B. symptoms must be present for over two years C. the afflicted individual must exhibit delirium at least 50 percent of the time D. plaques and tangles must be visible on an MRI