单项选择题
A battery-driven bus has been developed by a group of British companies. The bus, a fifty- passenger single-deck (1) , is to go into (2) in Manchester shortly, and discussions with the Department of the Environment are (3) to lead to a (4) batch (批) of twenty going into (5) passenger service in Manchester within two years. Unlike the small govemment- sponsored battery bus now (6) trials in provincial cities, (7) low speed and range effectively limits it to city centre operation, the new Silent Rider, (8) a range of 40 miles between charges and a (9) of 40 m.p.h., will take (10) place with diesel (柴油) buses for normal urban and suburban (11) .
Its capital (12) is higher (13) lower maintenance and fuel costs bring it (14) to a fully competitive cost with the diesel bus over a thirteen- year life，without (15) into account the environmental benefits．The Chloride battery group，which is developing (16) in partnership with SELNEC，is confident (17) a market potential of 400 vehicles a year．The bus weighs 16 tons， (18) which the batteries and passengers account for 4 (19) ．It has a single set of batteries， which take three and a half hours to (20) , against the normal eight hours of passenger traffic．
A. each
B. every
C. apart
D. once