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67 arrival [ə ’ raiv(ə)l] n появление loosen [ ’ lu:sən] v расшатываться loose [lu:s] a шатающийся successor [sək ’ sesə] n последователь predecessor [ ’ pri:disesə] n предшественник resorption [ri ’ s ɔ :p∫n] n рассасывание, резорпция deprive [di ’ praiv] v лишать (of) adjacent [ə ’ d ʒ eisənt] a прилегающий, смежный shed [∫ed] (shed, shed) v терять absorb [əb ’ s ɔ :b] v абсорбировать, поглощать, всасывать 24. Read the text. Make up your questions to the text. Eruption of the Teeth All teeth start developing inside the jaws and their arrival in the mouth is known as eruption. Deciduous teeth start developing before birth and erupt after birth. The frst deciduous tooth is one of the incisors. It should appear at the age of about six months. By the end of the second year a child is supposed to have a complete set of deciduous teeth. As we know they are twenty in number. Individual variation in eruption is common but the average ages are as follows: 1. Central incisor, 6 months. 2. Lateral incisor, 8 months. 3. Canine, 18 months. 4. 1 st molar, 12 months. 5. 2 nd molar, 24 months. Lower teeth usually erupt before their corresponding upper ones. Permanent teeth start developing at birth. Eruption commences at six years of age and is completed at eighteen to twenty-fiv years. Eruption times are subject to considerable individual variation but the average ages are: 1. Central incisor, 7 years. 2. Lateral incisor, 8 years. 3. Canine, 9 years (lower); 11years (upper). 4. 1 st premolar, 10 years (lower); 9 years (upper). 5. 2 nd premolar, 11 years (lower); 10 years (upper). 6. 1 st molar, 6 years. 7. 2 nd molar, 12 years. 8. 3 rd molar, 18–25 years.