Analogy: Needle is to Watch as Blade is to ____. Identify the object that commonly contains/uses the second component, paralleling the first pair.

Introduction / Context:
Component–device analogies pair a part with the object that contains or relies on it. A watch has “needles” (hands) indicating time. We must select the device that has blades as essential components.

Given Data / Assumptions:

• Watch → needles/hands.
• Device with blades → common household or mechanical device.

Concept / Approach:
A fan operates using blades that move air. Computers and books do not have blades; a car has many parts, but “blade” is not a defining, ubiquitous component in the same sense (except wiper blades, which are not central to operation).

Step-by-Step Solution:
Identify defining component: watch→hand; fan→blade.Eliminate devices where “blade” is non-essential or absent.

Verification / Alternative check:
Functional necessity: fan without blades cannot produce airflow; watch without hands (in analog type) cannot indicate time.

Why Other Options Are Wrong:
Computer/book: no blades. Car: not defined by blades; wipers are accessory parts.

Common Pitfalls:
Overgeneralizing “blade” to any sharp component in vehicles; the analogy seeks the primary, characteristic pairing.

Final Answer:
Fan.