Explanation:

- Unearthly typically means something otherworldly or not of this earth, often strange or supernatural.

- Option 1: Unnaturally strange

- This option reflects something peculiar or odd, aligning more with the connotation of unearthly rather than opposing it.

- Option 2: Spectral

- Usually refers to ghostly or phantom-like qualities, which are associated with supernatural or unearthly elements.

- Option 3: Supernatural

- Directly implies things that go beyond the laws of nature, closely related to unearthly themes.

- Option 4: Terrestrial

 This word means of the earth or belonging to the land, effectively the opposite of unearthly.

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