Modern bridges depend on careful damping to prevent destructive vibration. Engineers install heavy mass dampers, fluid-filled chambers, or tuned counterweights to absorb energy that would otherwise cause structural members to oscillate at dangerous resonance frequencies. The collapse of Washington State's Tacoma Narrows Bridge in 1940, attributed in part to inadequate damping under wind loading, motivated much of the engineering that followed.
Which choice best describes the function of the second and third sentences in the text?
- A
They contradict the importance of damping.
- Bcheck_circle
They support the importance of damping by listing techniques and citing a historical failure.
- C
They define the term 'bridge'.
- D
They introduce an unrelated structural form.
Explanation
Sentence two enumerates techniques; sentence three cites the Tacoma Narrows lesson. Both support the opening claim. B is correct.