Which of the following options is correct according to the reactivity of metals?

Which alloy is used for making aircraft parts?

Account for the following:
$(a)$ Aluminium is more reactive than iron,but its corrosion is less than iron.
$(b)$ Hydrogen gas is not evolved when zinc metal reacts with dilute $HNO_3$.
$(c)$ Carbon is not used for reducing aluminium from aluminium oxide.

$(a)$ What type of ores are calcined? Illustrate by giving a suitable example.
$(b)$ In what form is the calcined ore obtained,and how can it be reduced? Give chemical equations of the reduction process involved for the example provided by you.
$(c)$ Name two metals used as reducing agents by displacing metals of lower reactivity from their compounds.

State whether the following statement is true or false:
At ordinary temperature,the surfaces of metals such as magnesium,aluminium,zinc,lead,etc.,are covered with a thin layer of oxide which prevents the metal from further oxidation.

Which of the following non-metals is a liquid?