It may be necessary, in order that future【C1】______can enjoy clean air, that more of the【C

2】______is borne by long-term central government fund As air pollution varies enormously from place to place and can, indeed, be very local, it may also be necessary for the central government to【C3】______money so that local authorities can【C4】______special local problems. That these can be significant was shown by the report made in 1970【C5】______behalf of the London Boroughs Association. This【C6】______that in central London since 1958 smoke concentrations have decreased by 80 percent, whereas sunshine has increased by 70 percent and winter visibility has【C7】______threefold. There have been【C8】______in mortality and hospital admissions【C9】______with air pollution and in the response to it of bronchitis, as well as clear if less documented increases in plant types and bird【C10】______in the cities.

【C1】

A．habitats

B．inhabitants

C．inhabitant

D．inhabit