71．Farm dwellers in their isolation not only found it harder to locatecompanions in play but also thanks to the unending demands and pressures oftheir work, felt it necessary to combine fun with purpose.

(Farm dwellers…not only found it harder to…，but also…felt it necessary to…为句子主干)

单独居住的农场居民不仅发现在娱乐中很难找到伴侣，而且，由于来自工作的无休止的要求和压力，他们觉得必须把实用目的与乐趣结合起来。

分句1. Farmdwellers in their isolation not only found it harder to locate companions inplay

分句2. but alsofelt it necessary to combine fun with purpose.

分句3. thanks tothe unending demands and pressures of their work,

1和2并列

2和3嵌套