Explaining nasal bones :
OP's query:
For example there is only one nasal bone in a human body. While teaching bones in a human body to student before the skeleton model which sentence should I say by showing nasal bone?
1.There is only one of this bone in a human body.
2.There is only one example of this bone in a human body.
There are two nasal bones in a human body:
Ref. Google.
Humans have two nasal bones, which are small, symmetrical, oblong bones located in the upper-middle part of the face, between the upper jaw bones' frontal processes. They sit midline to each other to form the bridge of the nose.
The second sentence is correct because it implies that there is only one nasal bone in a human body, meaning that it's a unique bone, but it doesn't exclude the possibility that there might be another similar bone.
The first sentence is incorrect because it implies that there is only one bone of this type, which is not true. There are two nasal bones in the human body, one on each side of the face.