Answer:the Boundary of an advancing mass of warm air, in particular the leading edge of the warm sector of a low-pressure system.
Explanation:
Well theres not a question but a covalent bond is when you share electrons.
It B I just took the test ;)
Answer:
Francium (Fr), heaviest chemical element of Group 1 (Ia) in the periodic table, the alkali metal group. It exists only in short-lived radioactive forms.
Octane is the resistance of the burning of gasoline