There are more than 54,000 bridges in the United States that need to be repaired or replaced, a new study says.
원문출처 : http://www.cnn.com/2018/02/02/us/2018-structurally-deficient-bridges-trnd/index.html
원문출처 : http://www.cnn.com/2018/02/02/us/2018-structurally-deficient-bridges-trnd/index.html