【题目】In autumn, _________ the weather is often cool and fine, people living in the city always like climbing hills for outdoor activities to strengthen their health．
A．which B．where C．as D．when
在线课程【答案】D
【解析】
试题分析：考查副词。句意：在秋天，当天气变得凉爽，人们通常回去户外爬山来强健他们的身体。 A．which 哪个；B．where 哪；C．as 因为；D．when当。根据句意知选D。