What is associated with: as it has no mass this particle travels at about 186000 miles per second?

What is associated with: as it crosses oklahoma us highway 81 follows or parallels this famous 1800s cattle trail? Based on the clue 'as it happens produced by this network campaigns f...', what is the answer? Based on the clue 'as it has an atomic number of 66 the chemical elem...', what is the answer? Based on the clue 'as it has birdlike flapping wings leos flying mach...', what is the answer? Based on the clue 'as it has this many toes on each foot a raccoons f...', what is the answer? Based on the clue 'as it often turns out truth is stranger than this', what is the answer? Based on the clue 'as it permitted this practice william lloyd garris...', what is the answer? Based on the clue 'as it turned out the us didnt need the points from...', what is the answer?