Modern traffic lights are an American invention. Red-green systems were installed in Cleveland (1) 1914. Three-color signals were (2) in New York in 1918. They used (3) be operated by hand from a tower in the middle of the street. The first lights of this type appeared in London, on the junction between St. James Street (4) Piccadilly, in 1925. Automatic signals were installed a year later. In the past, traffic lights used to (5) very special. In New York, some lights used to (6) a statue...
Đọc tiếp
Modern traffic lights are an American invention. Red-green systems were installed in Cleveland (1) 1914. Three-color signals were (2) in New York in 1918. They used (3) be operated by hand from a tower in the middle of the street. The first lights of this type appeared in London, on the junction between St. James Street (4) Piccadilly, in 1925. Automatic signals were installed a year later. In the past, traffic lights used to (5) very special. In New York, some lights used to (6) a statue on top. In Los Angeles, the (7) did not just change silently, but would ring bells to wake the sleeping motorists of the 1930s. These are gone and have been replaced by modern systems that (8) seen everywhere now.
1 in
2 installed
3 to
4 and
5 be
6 have
7 lights
8 are
1.in
2.installed
3.to
4.and
5.be
6.have
7.lights
8.are