Help me with this _XX

B. Hardness

Explanation:

Physical properties of a substance is defined as the properties which can be observed or measured without changing the composition of matter.

Physical properties include odor, appearance, color, texture, boiling point, melting point and many others.

Hardness is a physical property of a substance as it describes the  resistance of substance to deformation and can be observed by simple touch or without changing the composition of matter.

While reactivity, toxicity and flammability are chemical properties of substances that change one type of matter into another type.

Hence, the correct option is B.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation:

a chain link fence because there so tiny even my albino donkey can't get out