答案及解析：
1. 文章标题分析：
Single-parent(单亲) kids do best
2. 直接解题
1. With which of the following statements would the author probably(可能)agree？
A. single mums produce(培育) stronger sons
B. single mums do not produce daughters
C. two-parent families produce less attractive children
D two-parent families produce more beautiful offspring(后代)
答案： C.
分析：问题问“作者可能会同意下列哪种说法？”注意到有3个被选项中都出现了比较级结构，因此推测答案可能出自它们之中， 同时注意关注文章中出现比较级结构的句子，这样找到答案相关句：(第一段)Single mums are better at raising(抚育) their kids than two parents – at least in the bird world. 该句说“单亲母亲比双亲能更好地抚育孩子”， 该句与被选项无关，所以接着看后面的句子： Mother zebra finches(斑胸草雀) have to work harder and raise fewer chicks (刚出生的小鸟)on their own(独自地)， but they also produce more attractive sons who are more likely to get a mate.该划线部分的结构说“它们(母斑胸草雀)能培育出更具有吸引力的雄性后代，而这些后代更可能找到配偶。”，根据该句内容判断C(由双亲家庭培育出的孩子具有的吸引力较小些)
2. According to (根据)the passage， in what way does family conflict (冲突)affect (影响)the quality of the offspring 后代？
A. the young males get less care(关心)
B. the young females will decrease(减少) in weight(重量)
C. the offspring will become lazy (懒惰的)fathers or mothers in the future(在未来)
D. the offspring will not get mature (成熟的)easily
答案： A.
分析：利用问题句中反映细节信息的结构family conflict和the quality of the offspring 作为答案线索，这样找到答案相关句：
(第2段) The findings shows that family conflict is as important an evolutionary driving force as ecological factors such as hunting and food supply. With two parents around， there’s always a conflict of interests(与family conflict呼应)， which can have a detrimental(有害的) effect on the quality of the offspring. 该划线句说“父母在身边就总会有利益的冲突，而这会给后代的质量产生坏的影响”，借助该句内容不能进行答案的判断，所以借助看后面的句子：
In evolutionary (进化的)terms， the best strategy (策略)for any parent in the animal world is to find someone else (其他人)to care for (照料)their offspring， so they can concentrate on (关注/专心)breeding(繁殖) again. So it’s normal (通常的)for parents to try to pass the buck to (把责任推卸给。。)each other(彼此)。 But Ian Hartley from the university of Lancaster and his team wondered (想知道)how family solve this conflict， and how the conflict itself affects the offspring.
To find out， they measured how much effort Zebra finch parents put into raising their babies. They compared single females with pairs， by monitoring the amount of food each parent collected， and removing or adding chicks so that each pair of birds was raising four chicks， and each mum had two – supposedly the same amount of work.