单选题 Regular child care provided outside home or by someone other than the mother does not in itself undermine(削弱) healthy emotional connections between mothers and their 15-month-old infants, according to a long-term national study. The finding holds even if care begins during the first 3 months after birth and runs for 30 hours or more per week.
Among infants who receive unkind and unresponsive care from their mothers, however, the mother-child relationship may be damaged. "This research helps us put apart complexities regarding child care that have not previously been studied in detail." contends Jay Belsky, a psychologist at Pennsylvania State University. Belsky and several of his colleagues announced their findings last week at the international conference.
The investigation consists of 1 153 children and their families living in or near Boston. The youngsters, no more than 1 month old when they entered the study in 1991, will be tracked until the age of 7. Experimenters administered questionnaires to mothers in their homes and videotaped baby caretakers interacting with the kids at ages 1, 6, and 15 months. Independent observers rated the quality of each child care efforts and noted infant nervousness. Unlike most previous studies, this one allows researchers to observe each caretaker's personality at child nursing, and kids' emotional reaction by the equipment.
After taking family factors into account, other psychologists state that the researchers found no relation between the quality of child care and infants' response. But the experimenters contend that the boys who spent more than 30 hours per week in child care exhibited more emotion for their mothers than other boys who didn't, and the girls who spent the same hours per week in child care showed a modest rise in this emotion. Therefore, quality of child care outside home plays an important role in the connection between mothers and infants.

单选题 From the first paragraph we know that ______.
【正确答案】 C
【答案解析】这是一篇议论文。文章从心理分析等角度对婴儿护理质量与婴儿素质的关系进行了调查研究、分析，并得出其他相应的结论。
这是一道语篇理解题，我们从第一段可知，“家庭外的幼儿照顾或定期由他人代管幼儿，不会影响孩子和母亲间的良好感情联系”。由此可推测C项为正确答案。
单选题 Jay Belsky implies that the study of child care ______.
【正确答案】 B
【答案解析】这是一道语篇理解题。文章第二段告诉我们：This research helps us put apart complexities regarding child care that have not previously been studied in detail．即“此项研究就关于照顾孩子的一些复杂问题提出了独到的见解，而在此之前，人们尚未对此做过深入的调查研究”。故选择B项。 ．
单选题 The main difference between the investigation and the previous ones is that ______.
【正确答案】 D
【答案解析】这是一道细节理解题。文章第三段最后一句告诉我们，“与以往的研究不同，这次允许研究者们借助工具、设备来观察育儿员在照顾幼儿时的具体表现，以及孩子们的情感反应”。
单选题 The girls who received the same hours of child care outside home as the boys demonstrated ______.
【正确答案】 A
【答案解析】这是一道语篇理解题。文章最后一段告诉我们，“和男孩接受同样时间的家庭外照顾的女孩子，更想得到母亲感情上的抚慰”。