For the following question, arrange the sentences A, B, C, and D between sentences 1 and 6 to form a logical sequence with sentence 1 and sentence 6 as the starting sentence and the concluding sentence respectively:
(1) Urban problems differ from city to city.
(A) As a result, most of the cities face a shortfall in drinking water as well as electricity.
(B) The population in these cities has grown far beyond what they had been planned for.
(C) However, certain basic problems are common to all cities.
(D) The number of vehicles on roads has grown at a phenomenal rate in most cities.
(6)
And the roads are simply not wide enough to accommodate them.