Answer:
<h2>Focal length</h2>
Explanation:
The Focal length of a lens is the distance from the center of the lens to
its principal focus.
Answer: Proxima Centauri is the closet star about 40,208,000,000,000 km away.
Explanation:
Iron nail. the rest of those are not iron or some form of magnetic material.
Answer:
Explanation:
Given
mass of children 
distance between two children 
suppose small child is at a distance of x m from pivot point
so torque of small child and heavier child must be equal
Answer: When a pathogen enters their colony, ants change their behavior to avoid the outbreak of disease. In this way, they protect the queen, brood and young workers from becoming ill. These results, from a study carried out in collaboration between the groups of Sylvia Cremer at the Institute of Science and Technology Austria (IST Austria) and of Laurent Keller at the University of Lausanne, are published today in the journal Science.
Explanation: search for it.
