Metal is a good conductor of heat but air is a poor conductor of heat.
Explanation:
Touching the metal sides of the oven can be harmful while holding our hand briefly in the oven air is okay. This tells us about the relative conductivities of metal and air <em>that metal is a good conductor of heat but air is a poor conductor of heat</em>. Conduction is the transference of heat through physical contact. Not all materials conduct heat in the same way. The best conductors of heat are metals and stone.
He was separated in certain classes and he will attend academic classes only with students whose general academic achievement is the same as his own. This is useful because it enables teachers to cater their objectives toward a specific ability level of the students.