the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur

the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur

the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur

the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur

a conference of people who are in different locations that is made possible by the use of such telecommunications equipment as closed-circuit television

a conference of people who are in different locations that is made possible by the use of such telecommunications equipment as closed-circuit television

a conference of people who are in different locations that is made possible by the use of such telecommunications equipment as closed-circuit television

vegetation (such as young shoots, twigs, and leaves) that is suitable for animals to eat

vegetation (such as young shoots, twigs, and leaves) that is suitable for animals to eat

vegetation (such as young shoots, twigs, and leaves) that is suitable for animals to eat