This question tests your understanding of participle adjectives and appropriate word choice in context.

The sentence structure requires us to fill two blanks:

1. The first blank needs a word that describes the minerals and foodstuffs

2. The second blank needs a word that describes the type of countries

Step 1: Analyze the first blank

The phrase "minerals and foodstuffs _____ by" requires a past participle because it describes products that are needed (passive voice). "Needed" is the correct past participle form meaning "required" or "in demand."

Step 2: Analyze the second blank

The phrase "the _____ countries" requires an adjective describing the type of countries. "Industrialized" is the correct adjective meaning countries that have developed industries.

Final Answer: The correct option is "needed / industrialized"

The complete sentence reads: "The developing countries that are producers of primary products are those that have minerals and foodstuffs needed by the industrialized countries."

Related Concepts

Participle Adjectives: Past participles (ending in -ed) often describe how someone or something is affected (e.g., needed, wanted, loved). Present participles (ending in -ing) describe what causes the feeling (e.g., needing, wanting, loving).

Word Forms: Understanding the correct form of words (verb, adjective, noun) is crucial for sentence completion. "Industrialized" functions as an adjective, while "to industrialize" is an infinitive verb form.

Key Formula/Pattern

Passive construction pattern: noun + past participle + by + agent

Example: products + needed + by + countries