墨尔本PTE Summarize written text 总结归纳段落 06

Read the passage below and summarize it using one sentence. You have 1 0 minutes to finish this task. Your response will be judged on the quality of your writing and on how well your response presents the key points in the passage.

A country’s standard of living generally depends on the size of its national income. Standards of living are measured by such things as the number of cars, televisions, telephones, computers, washing machines, and so on, for every one thousand people. There is, however, no standard international index, which is why national income figures are used as a substitute. But the use of these figures to compare the standard of living between countries needs to be done carefully, because they are, at best, only a rough guide which can be misleading. The main problem here is that it is necessary to have a common unit of measurement if any sort of comparison is to be made at all. It has become the custom to use the dollar, and each country’s currency is converted at its official exchange rate into a national income figure in dollars. Now, since the exchange rate is often set at an artificial level in relation to dollars, you are likely to end up with a figure that is useless for your purposes.