Meaning: A 'substance' refers to a particular kind of matter with uniform properties, in this case, lava.

Wrong options:

• render: The word 'render' is a verb that means to cause to become, which does not fit as it does not describe what lava is.
• fuse: 'Fuse' is a verb that means to join together, which does not appropriately describe lava in this context.
• melt: 'Melt' is a verb that refers to the process of becoming liquid, which does not fit as a noun to describe lava.
• erupts: 'Erupts' is a verb that describes an action, not a noun, and therefore does not fit in this context.
• navigates: 'Navigates' is a verb that means to find one's way, which does not relate to the description of lava.
• model: 'Model' is a noun that refers to a representation, which does not accurately describe lava.

Correct answer: erupts

Explanation: The word 'erupts' is a verb that fits grammatically as it describes the action of lava coming out of a volcano. It is contextually appropriate as it describes the process that follows lava rising to the surface.

Meaning: To 'erupt' means to burst forth suddenly and violently, as in the case of lava from a volcano.

Wrong options:

• render: 'Render' is a verb that means to cause to become, which does not fit as it does not describe the action of lava.
• substance: 'Substance' is a noun and does not fit as a verb to describe the action of lava.
• fuse: 'Fuse' is a verb that means to join together, which does not accurately describe the action of lava.
• melt: 'Melt' is a verb that refers to the process of becoming liquid, which does not fit as an action describing lava's behavior.
• navigates: 'Navigates' is a verb that means to find one's way, which does not relate to the action of lava.
• model: 'Model' is a noun that refers to a representation, which does not fit as a verb in this context.

Correct answer: melt

Explanation: The word 'melt' is a verb that fits grammatically as it describes the action that lava can perform on solid rock. It is contextually relevant as it explains one of the effects of lava's extreme heat.

Meaning: To 'melt' means to change from a solid to a liquid state due to heat.

Wrong options:

• render: 'Render' is a verb that means to cause to become, which does not fit as it does not describe the action of lava on rock.
• substance: 'Substance' is a noun and does not fit as a verb to describe the action of lava.
• fuse: 'Fuse' is a verb that means to join together, which does not accurately describe the effect of lava on solid rock.
• erupts: 'Erupts' is a verb that describes the action of lava coming out of a volcano, which does not fit in this context.
• navigates: 'Navigates' is a verb that means to find one's way, which does not relate to the action of lava.
• model: 'Model' is a noun that refers to a representation, which does not fit as a verb in this context.

Correct answer: render

Explanation: The word 'render' is a verb that fits grammatically as it describes the action of making something into a different state, in this case, solid rock being affected by lava. It is contextually appropriate as it describes the transformative effect of lava.

Meaning: To 'render' means to cause to become or to make, particularly in a transformative sense.

Wrong options:

• substance: 'Substance' is a noun and does not fit as a verb to describe the action of lava.
• fuse: 'Fuse' is a verb that means to join together, which does not accurately describe the effect of lava on solid rock.
• melt: 'Melt' is a verb that refers to the process of becoming liquid, which does not fit as it describes a different action than rendering.
• erupts: 'Erupts' is a verb that describes the action of lava coming out of a volcano, which does not fit in this context.
• navigates: 'Navigates' is a verb that means to find one's way, which does not relate to the action of lava.
• model: 'Model' is a noun that refers to a representation, which does not fit as a verb in this context.