Green space facilities are contributing to an important extent to the quality of the urban environment. Fortunately it is no longer necessary that every lecture or every book about this subject has to start with the proof of this idea. (46)At present it is generally accepted , although more as a self-evident statement than on the basis of a closely-reasoned scientific proof. The recognition of the importance of green space in the urban environment is a first step on tile right way. (47)This does not mean, however, that sufficient details are known about the functions of green space in towns and about the way in which the inhabitants are using these spaces. As to this rather Complex subject I shall, within the scope of this lecture, enter into one aspect only, namely the recreative function of green space facilities.
(48) The theoretical separation of living, working, traffic and recreation which for many years has been used in town-and-country planning, has in my opinion resulted in disproportionate attention for forms of recreation far from home, whereas there was relatively little attention for improvement of recreative possibilities in the direct neighborhood of the home. (49)We have come to the conclusion that this is not right, because an important part of the time which we do not pass in sleeping or working, is used for activities and around home. So it is obvious that recreation in the open air has to begin at the street door of the house.
(50)The urban environment has to offer as many recreation activities as possible, and the design of these has to be such that more obligatory activities can also have a recreative aspect. The very best standard of living is nothing if it is not possible to take a pleasant walk in tile district, if the children cannot be allowed to play in the streets, because the risks of traffic are too great, if during shopping you can nowhere find a spot for enjoying for a moment the nice weather, in short, if you only feel yourself at home after the street-door of your house is closed after you.
(47)This does not mean, however, that sufficient details are known about the functions of green space in towns and about the way in which the inhabitants are using these spaces.
参考答案：
[参考译文] 然而，这并不意味着，我们对于有关城镇中绿色空间的作用以及居民使用这些空间的方法有了足够的了解。
解析：
句子框架是This does not mean…that…。that引导的从句作mean的宾语。从句中的被动结构be known译成主动句，增译泛指性的主语“我们”。句尾的介词短语about the way中又嵌套了一个介词in加关系代词which引导的定语从句，修饰the way。