When you visit London, one of the first things you will see is Big Ben, the famous clock which can be 21 all over the world on the BBC. If the House of Parliament had not been burned down in 1834, the great clock would never have been erected. Big Ben takes its name from Sir Ben Gamin Hall who was responsible 22 the making of the clock when the new House of Parliament was 23 . It is not only 24 , but is extremely accurate 25 . Officials from Greenwich Observatory（格林威治天文台）have the clock 26 twice a day. On the BBC you can hear the clock when it is actually 27 because microphones are connected to the clock tower. Big Ben has 28 gone wrong. Once, however, it failed to give the correct time, a painter who had been __29 the tower bung a pot of paint on one of the hands and the clock was 30 ! 21. _______ [

A、 ] seen [

B、 ] felt [

C、 ] heard[

D、 ] touched

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