Respuesta :
Both 1 and 2 are a characteristic of all mammals.
What are the characteristics of mammals?
Characteristics of Mammals are:
- The presence of hair or fur.
- Sweat glands.
- Glands are specialized to produce milk, known as mammary glands.
- Three middle ear bones.
- Specialized teeth.
- A four-chambered heart
Thus, Both 1 and 2 are a characteristic of all mammals.
To learn more about Mammals click here:
https://brainly.com/question/10194338
