3. Above all, like their female human counterparts,they tend to pay much closer attention to the value of "goods and services" than males.

【分析】简单句。句子主干为they tend to pay much closer attention to…。介词短语 like...counterparts作方式状语。整个句子是一个含比较结构的主谓宾句型。
【译文】最重要的是，就像人类当中的女性一样，它们(雌性猴子)往往比雄性更关注“商品和服务”的价值。
【点拨】1）counterpart在句中意为“与对方地位相当的人，与另一方作用相当的物”，还有“副本，复本”意思。2）tend to do “易于...,往往会...”。

4. However, when two monkeys were placed in separate but adjoining chambers,so that each could observe what the other was getting in return for its rock, their behavior became markedly different.

【分析】多重复合旬。本句主干为their behavior became markedly different。句子中包含when引导的时间状语从句以及so that引导的目的状语从句，目的状语从句中又包含what引导的宾语从句。
【译文】但是，当两个猴子被安置在隔开但相邻的两个房间，能够互相看见对方用石头换回什么东西时，它们的行为就会变得明显不同。