①a period of infertility
②According to his results,published in Proceedings of the Royal Society B,the much-vaunted joys of grandmotherhood are no certain thing.
③groupmate
④XX's data,therefore,show that despite their differences,both whale and human societies favour atransition to sterile nannyhood.
麻烦各位了~
the much-vaunted joys什么意思呢?字面意思是引以为豪的乐趣?