Meaning: 'Hosted' means to have provided a place or environment for something, in this case, life forms.

Wrong options:

• shielded: 'Shielded' is a past participle that describes protection, which does not fit as it does not relate to the concept of providing a habitat for life.
• multiplying: 'Multiplying' is a present participle that indicates an ongoing action, which does not fit the past context of the sentence.
• resulting: 'Resulting' is a present participle that indicates a consequence, which does not fit the context of hosting life.
• obtained: 'Obtained' is a past participle that means to have acquired something, which does not relate to the idea of providing a habitat.
• offered: 'Offered' is a past participle that means to have presented something, which does not fit the context of hosting life.

Correct answer: shielded

Explanation: The word 'shielded' serves as a past participle that describes how the organisms were protected from harmful radiation. It fits grammatically and contextually as it describes the condition of the organisms' environment.

Meaning: 'Shielded' means protected from harm or danger, in this case, from radiation.

Wrong options:

• hosted: 'Hosted' does not fit here as it refers to providing a habitat, not protection from radiation.
• multiplying: 'Multiplying' is a present participle that indicates an ongoing action, which does not fit the context of being protected.
• resulting: 'Resulting' is a present participle that indicates a consequence, which does not fit the context of describing protection.
• obtained: 'Obtained' is a past participle that means to have acquired something, which does not relate to the idea of being shielded.
• offered: 'Offered' is a past participle that means to have presented something, which does not fit the context of protection.

Correct answer: multiplying

Explanation: The word 'multiplying' is a present participle that indicates the ongoing action of the organisms increasing in number. It fits grammatically and contextually as it describes the growth of life forms over time.

Meaning: 'Multiplying' means increasing in number or quantity, referring to the growth of microbes.

Wrong options:

• hosted: 'Hosted' is a past participle that does not fit here as it does not describe an ongoing action of growth.
• shielded: 'Shielded' is a past participle that describes protection, which does not fit the context of growth.
• resulting: 'Resulting' is a present participle that indicates a consequence, which does not fit the context of describing growth.
• obtained: 'Obtained' is a past participle that means to have acquired something, which does not relate to the idea of increasing in number.
• offered: 'Offered' is a past participle that means to have presented something, which does not fit the context of growth.