Step 1: Understanding the Correct Word Choice
The correct option is "many" because "many" refers to a large number of parts, which is suitable in this context. The sentence is referring to multiple areas or sections of the world, and "many" appropriately describes the quantity of these parts.
Step 2: Evaluating the Other Options
- "Little" refers to a small amount, which is not appropriate when referring to the plural noun "parts" in this context.
- "Neither" is used to refer to two items, but the sentence mentions multiple parts, so it is not suitable.
- "Each" refers to individual items or entities, which does not match the context of describing multiple parts of the world collectively.
Step 3: Conclusion
Thus, the correct sentence is: "Clean water is a precious commodity in many parts of the world."