题目内容：

How much weight a baby gains during its first month could determine its IQ, new research found. The study found that children who gain more weight, and whose heads grow quickly during the first month of life, tend to have a higher IQ when they start school.

Researchers at the University of Adelaide, in Australia studied 13, 800 children who were born at full-term. They found that those who put on 40% of their birth weight in the first four weeks had an IQ 1.5 points higher than those who only put on 15% of their birth weight. Those who experienced the biggest growth in head circumference(头围) also had the highest IQs by the age of six.

"Head circumference is an indicator of brain volume, so a greater increase in head circumference in a newly-born baby suggests more rapid brain growth, "says the author of the study, Dr. Lisa Smithers. She added, "Overall, newly-born children who grew faster in the first four weeks had higher IQ scores later in life. Those children who gained the most weight scored especially high on the verbal IQ at age 6. This may be because neural (神经的) structures for the verbal IQ develop earlier in life, which means the rapid weight gain during the first month could be having a direct cognitive benefit for the children."

Previous studies have shown the association between early postnatal (产后的) diet and the IQ, but this is the first study of its kind to focus on the IQ benefits of rapid weight gain in the first month of life. Dr. Lisa Smithers says the study further highlights the need for successful feeding of newly-born babies." We know that many mothers have difficulty establishing breastfeeding in the first week of their babies' life,” Dr. Lisa Smithers said.

"The findings of our study suggest that if babies are having feeding problems, there needs to be early intervention(干预) in the management of that feeding."

1.How did the researchers get their conclusion from the study?

A. By asking questions    B. By making comparison

C. By having a discussion    D. By referring to documents

2.According to Dr. Lisa Smithers, we can learn that___.

A. a kid's verbal IQ scores reach its highest at age six

B. this study helps parents find feeding problems

C. quick weight gain benefits newly-born babies on the verbal IQ

D. this study reminds parents of the need for breastfeeding

3.The study differs from previous ones that ___.

A. it associates early postnatal diet with the IQ

B. it pays attention to the IQ of newly-born babies

C. it emphasizes the significance of successful feeding

D. it first focuses on the relation between the IQ and weight gain in the first month of life