Enamel of teeth is secreted by:
1.  Ameloblast
2.  Odontoblast
3.  Osteoblast
4.  Osteoclast

Lower jaw is composed of:
1.  Dentary
2.  Maxilla
3.  Premaxilla
4.  Palatine

The dental formula of an adolescent human being before seventeen years of age:

1. $\frac{2122}{2122}$

2. $\frac{2123}{2123}$

3. $\frac{2102}{2102}$

4. $\frac{2023}{2023}$