题目内容：

    Parents tend to favour children of one sex in certain situations — or so evolutionary biologists tell us. A new study used colored backpack sales data to show that parental wealth may influence spending on sons different from daughters.

In 1973 biologist Robert Trivers and computer scientist Dan Willard published a paper suggesting that parents invest(投入)more resources, such as food and effort, in male children when times are good, and in female children when times are bad. According to the Trivers-Willard hypothesis(假说), a son given lots of resources can become a gentleman — but parents with few resources tend to invest them in daughters, who generally find it easier to be a fair maiden.

Studying parental investment after birth is difficult, however. The new study looked for a standard of measurement of such investment that met several criteria: it shouldn’t be affected by sex differences in the need for resources; it should measure investment rather than outcomes; and it should be objective.

Study author Shige Song, a sociologist at Queens College, City University of New York, examined spending on pink and blue backpacks purchased in China in 2015 from a large retailer, JD. com. He narrowed the data to about 5, 000 bags: blue backpacks bought by families known to have at least one boy and pink ones bought by families known to have at least one girl. The results showed that wealthier families spent more on blue than pink backpacks — suggesting greater investment in sons. Poorer families spent more on pink packs than blue ones. The findings were published in Evolution and Human Behavior.

Song’s evidence for the Trivers-Willard hypothesis is “indirect” but “pretty convincing,” says Rosemary Hopcroft, a sociologist at the. University of North Carolina at Charlotte, who was not connected with the new study. Hopcroft reported in 2016 that U. S. fathers with high-status occupations were more likely to send their sons to private school than their daughters, while fathers with lower-status jobs more often enrolled their female children. Although the new study does not prove the families were buying the blue backpacks for boys and pink ones for girls, Hopcroft notes that “it’s a clever and interesting paper, and it’s a rather unusual use of big data.”

1.What does the writer intend to do in Paragraph 2?

A. Introduce an earlier study.

B. Identify children’s needs.

C. Assess the influence of a study.

D. Explore into parental investment.

2.What offers a challenge for the new study?

A. The investment meeting several criteria.

B. The measurement of eventual outcomes.

C. Different demands for resources between sexes.

D. Consistent standards in measuring parental investment.

3.What can be learned from Song’s research?

A. The new study was done in 2015.

B. Big data was sampled for research.

C. Preference was offered to consumers.

D. Blue packs were favored over pink ones.

4.Which of the following is likely to match Hopcroft’s remark on Song’s research?

A. It’s entertaining. B. It’s well-designed.

C. It’s unbelievable. D. It’s unusual.