阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
A
Since it first opened after four years of construction in 1937 at a cost of $27 million，the Golden Gate Bridge has made its appearance in films and poetry.
CNN Travel spent a day climbing into and ground the bridge，learning these secrets from the people who know and love it best.
Why is it called the Golden Gate Bridge? It's not golden.
“The Golden Gate Bridge gets its name because it spans what is called the Golden Gate Strait，”said Paolo CosulichSchwartz，spokesman for the Golden Gate Bridge，Highway and Transportation District，which operates the bridge. It's a threemilelong and onemilewide body of water that connects the Pacific Ocean to the San Francisco Bay.
What color is the bridge? It looks red.
“It's not red，although you're not crazy to think so. Visitors all call it red，”said Russell. “Back in the day，the US Navy，then part of the War Department，oversaw the waterways and wanted to paint this bridge black and yellow for high visibility，”said fellow painter Jarrod Bauer. “They ended up mixing paint to create the color International Orange，which is similar to the color of red lead，”he said.
Does the bridge get entirely painted every year?
No，and it doesn't need to be. It's true that the top coat has been fully repainted over time with new and environmentallyimproved International Orange top coats.
Who performs bridge rescues?
McVeigh and his fellow ironworkers，the socalled “Cowboys of the Sky”，have that responsibility. McVeigh has lost count of how many troubled souls he's been called to rescue over the past 17 years.
In September in 2018，the bridge started constructing a suicide(自杀)prevention system，also known as the safety net，to keep people from jumping off the Golden Gate Bridge. It's expected to be completed in 2021.
21．What's the true color of the Golden Gate Bridge?
A．Red. B．Red lead.
C．Black and yellow. D．International Orange.
22．Who can probably be called a hero on the Golden Gate Bridge?
A．McVeigh. B．Jarrod Bauer. C．Russell. D．Paolo.
23．What can we know about the Golden Gate Bridge?
A．It is safer now because of the safety net. B．It got its name because of its color.
C．It took much time and money to be built. D．It needs to be repainted once a year.
