In a kind of animal tissue all cells rest on a basement membrane, but the basal cells do not reach the free surface of the epithelium. Two layers of cells and two layers of nuclei are, therefore, observable. Thus, without being stratified, the epithelium appears to have 2 or 3 layers of cells. Such epithelia are mostly ciliated and contain mucus-secreting goblet cells. These epithelia are characteristic to which of the following?