Concern About the Greenhouse Effect Stems from

question 30

Multiple Choice

Concern about the greenhouse effect stems from

• A) Increases in volcanic ash in the air.
• B) Increases in atmospheric carbon-dioxide levels.
• C) Worldwide cooling observed since the 1920s.
• D) Falling sea level.

---

Definitions:

Hollow Box-Section

A hollow, box-shaped section of material, often metal or plastic, used in construction and manufacturing for its strength and lightweight characteristics.

Beam Axles

A type of axle design where a single piece runs across the vehicle, supporting the wheels on opposite sides, typical in certain trucks and older vehicles.

Hollow Round-Section

A type of structural component characterized by its round, tubular shape with a hollow center, commonly used in various engineering and construction applications.

Single Reduction

In mechanical systems, a gear arrangement where speed reduction and torque increase are accomplished in one single step or stage.