题目内容：
根据短文内容，回答题。What do we mean by a satisfactory standard of living7 Obviously, it must include the basic necessities of life such as food, clothing and shelter. To get these necessities on regular basis, a person must have a reliable income: But we have other needs which would probably also be included as basic, such as health and education facilities.
We may think of all of these as our needs. Yet most of us would be far from satisfied if we had nothing more than these which are supplied for us. We all enjoy extra income to spend on things like books, sports or hobbies. Sometimes we save some of this-extra income to pay for future expense of this type on holidays. So we must add our wants to our basic needs. Our standard of living is the degree, to which these needs and wants are satisfied.
But as time goes on, what we think of as our basic needs changes. Twenty years ago a television would have been a luxury, and still is in many countries now. Even now we cannot say it is a need in the same sense as food, clothing and shelter, Yet if most of the people of a country have one, it comes to be accepted as a need. It is possible therefore to have food, clothing and shelter and still be poor by the standards of our own society.
What we need in life is divided into __________ according to this article. A．the basic necessities and luxury
B．many kinds of need such as food, clothing and houses
C．four groups the basic necessities, luxury, reliable inc0me and future expense
D．the basic necessities and reliable income
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