Ex.22. Complete the text with the words in the box

Your child's _______ teeth are extremely important. Without them your child cannot ______ food properly and will have difficulty learning to speak clearly. A deep cavity in a baby tooth can cause a lot of ______ that a young child may not be able _____________about to the parent properly. Severe _____________ may result from untreated cavities. Untreated cavities in primary teeth can also adversely affect the development of ____________ teeth. Such cavities result in a roughening of adult teeth, or cause permanent teeth that ___________ with cavities. Baby teeth also serve to reserve space for permanent teeth and guide new tooth ____________in a proper direction. If a baby tooth is lost too ___________, new teeth may grow in crooked.

Ex.23. Read the following text and entitle it:

At birth, baby’s 20 primary teeth are present in the baby's jawbones and the crowns of these primary teeth are almost complete. Usually, the front four teeth will begin to "erupt" between age 6 months and one year. By age three, most children have a full set of 20 primary teeth. The primary teeth play an important role in the child's ability to chew and speak and in the child's appearance. Also, the primary teeth are useful in holding space in the jaws for the permanent teeth.

As a child approaches age six, the jaw is growing to make room for the permanent teeth. As this happens, the roots of the permanent teeth are beginning to be absorbed by the surrounding tissue and the permanent teeth prepare to erupt.

Between ages five and six, the first permanent molars usually erupt. These molars are also called, "six-year" molars.

These molars do not replace any primary teeth and are especially important because they help determine the lower part of a child's face and affect the position of the other permanent teeth. By age 21, all 32 permanent teeth usually will have erupted.

Ex.24. Read and translate the following text: