题目内容：

It has long been thought that first-born children are more successful than their younger brothers and sisters and often have qualities of being more organised and responsible as well as being eager to be in charge.

But a new study has shown that the elder child's achievements can help improve their younger siblings(兄弟姐妹) exam results by helping them to raise their game. For the first time ever, researchers from the University of Essex examined how the success of first born children in school affected their younger brothers and sisters by studying primary school test results.

And the data showed that having an older brother or sister improved a child’s learning with the equal effect of spending an extra £670 on the younger sibling's schooling. One of the study’s authors Birgitta Rabe explained, the older sibling’s achievement may have a direct effect on the younger sibling’s school grades if the older sibling teaches the younger sibling or helps with homework; the younger sibling imitates(模仿) the older sibling, for example in their work style, or tries to be different, for example to avoid competition; the older sibling passes on important information about educational choices or school and teachers to the younger sibling.

The effect is even more noticeable in less well-off families showing poorer children benefit more from a successful older sibling. “We find that the effect is larger for siblings in families relying on free school meals, living in poverty and speaking a language other than English at home. This means that children who live in poverty benefit more from a successful older sibling than children who live in well-off families.”

1.The study is mainly based on the children’s ________.

A. exam results        B. work style

C. family background    D. educational choices

2.According to the study, ________ tend to benefit more from a successful older sibling.

A. the children who live in rich families

B. the children who live in poor families

C. the children whose parents are successful

D. the children whose mother language is English

3.What can we conclude from the study?

A. Younger siblings are more successful than first borns.

B. First-born children are as successful as their younger siblings.

C. First-born children are more successful than their younger siblings.

D. The success of first borns has positive effects on their younger siblings.

4.The passage is likely to appear in ________.

A. a newspaper advertisement

B. a high school textbook

C. a science magazine

D. a news report