1: Where is the hard palate? 2. What is the difference between the upper teeth and the back of the upper teeth? 3. What is the prominent part of the upper mouth? 4: tongue.

The hard palate is located in the first two-thirds of the palate. Its bony basis is the palatal process of maxilla and the horizontal plate of palatal bone, and its surface is covered with mucosa. Palate is the upper wall of oral cavity, which is divided into soft palate and hard palate. Hard palate is based on bone and covered with mucosa. The soft palate is connected with the hard palate and consists of muscles and mucous membranes. There is a drooping protrusion in the center of its trailing edge, which is called uvula.

The upper teeth refer to the whole upper teeth, and the back of the upper teeth refers to the back of the upper teeth, that is, the back part.

There is no detailed distinction between the front and back of the tip of the tongue. If it is related to English pronunciation, it also refers to the different positions of the pronunciation tongue. Pronounce of the tip of the tongue is a consonant produced by the obstruction of the tip of the tongue to the back of the upper incisors. Relative to the upper gum, the back of the upper incisor is located in front (close to the lips), so the sound relative to the tip of the tongue to the upper gum is called the front sharp sound. The middle tone of the tip of the tongue is formed by the obstruction of the tip of the tongue and the upper gum to the airflow of pronunciation. There are four initials, D, T, N and L. The retrolingual consonant refers to the consonant produced by retrolingual movement, which is in contact with the back of the gum and constitutes an obstacle.