There are some things money can't buy.Education，however，does not appear to be among them—at least as measured by performance on international exams.A new study by Harvard University offers strong evidence that the wealth of a country affects exam results just as much as the wealth of a pupil's household does.On average，pupils in wealthy countries obtain vastly higher test scores than those in developing ones.
    Evaluating test scores around the world is harder than it sounds.Although pupils in the rich world mostly take one of a few big international exams，many developing countries rely on regional tests，making apples-to-apples comparisons impossible.
    Researchers organized an exam in 2016 for 2，314 children in India，which included both questions from the leading tests and ones taken from smaller exams.Using answers from the same pupils on the same day to questions from different tests，they built a statistical model they called a "Rosetta Stone".It can translate scores from a range of exams—such as one used only in west Africa—into an equal mark on other common international tests.
    They then used these equations（等式）to estimate how pupils in 80 different countries would fare on the benchmark（基準(zhǔn)）Trends in International Mathematics and Science Study （TIMSS）.Their data show that the wealth of a student's country and family have similar impacts on test scores—meaning that big gaps in GDP per person matter more than small ones in household income do.For example，pupils from families that are very poor by rich-world standards—those earning ﹩5，000 a year—are expected to score around 500 out of 1，000 on the TIMSS in America，and 560 in Japan.In contrast，those whose parents make ﹩10，000 a year in an upper-middle income country can only get the equivalent（等價物）of a 475.
    The influence of parental earnings is not constant.Rich people tend to educate their children privately in places where wealth is concentrated，such as Brazil.However，in countries with relatively flat income distributions，like Croatia，pupils from different social classes are more likely to attend the same schools.This could reduce the impact of family wealth on test scores.

（1）Why is it hard to evaluate the exam scores on a global level？

A

A

A．Because the types of exams vary with countries.
B．Because many rich countries refuse regional tests.
C．Because the wealth of a country affects exam results.
D．Because no international exam is available to poor areas.
（2）Why did the researchers establish a "Rosetta Stone"？

D

D

A．To integrate different exams into a common one.
B．To evaluate different exams with distinct approaches.
C．To fix the standard of the exams in different countries.
D．To turn scores of different exams into an equivalent mark.
（3）What can we learn from the last two paragraphs？

C

C

A．Poor students tend to be academically superior to rich ones.
B．Students from rich families will definitely get higher grades.
C．The influence of family income on students is related to circumstances.
D．People with high social status are more likely to educate their children privately.
（4）What is the text mainly about？

B

B

A．Education is something money can't buy.
B．The wealth of a country matters for education.
C．Family income plays an important role in education.
D．A statistical model helps to evaluate the exam scores.