閱讀下面材料，在空白處填入適當(dāng)?shù)膬?nèi)容（1個單詞）或括號內(nèi)單詞的正確形式。

Walking down the city streets, you look up and see a red telephone box. Behind it, on the road, a big red double-decker bus passes by, 1. _______ (carry) citizens and tourists. This is London. And the red bus has been a long-standing icon of the city.

Modern transportation has changed the way we live 2. _______ lives. One important mode of transport has been the bus. In London, buses take on a bigger role. They are used 3. _______ (tour) the city. Red tourist buses have open roofs, 4. _______ let people take many photos as they drive past Big Ben, the Thames, the London Eye, and so on.

But how did the bus become unique 5. _______ London culture? Horse-drawn buses have been used in London since 1829. By the early 20th century, motor-buses were driving around London. Bus companies used different colors at the time. The 6. _______ (big) company chose red. In 1933, when London transport was grouped into a single company, they chose the most 7. _______ (wide) used color at the time – red.

And so the color red stayed in London. But it was during the mid-1950s 8. _______ the red double-decker was born. Its name is the Routemaster. All of them 9. _______ (build) between 1954 and 1968. That is why they still look 10. _______ (tradition). Like they have been frozen in time.

Keys:

1. carrying 2. our 3. to tour 4. which 5. to 6. biggest 7. widely 8. that 9. were built 10. traditional