例句與造句

1. Earlier research suggested that smoking behaiors tend to cluster in families , and large studies of twins preiously concluded that the clustering is partly related to genetic factors
   早期的研究表明抽煙行為有家庭聚集的傾向，以前大量的雙胞胎試驗(yàn)得出聚集僅部分由于遺傳因素引起。
2. It's difficult to find clustering in families in a sentence. 用clustering in families造句挺難的