【题目】Most of the visitors were happy just sitting around in the shade, _________ it had been a long, dusty journey on the train.
A. for B. so C. but D. Or
在线课程【答案】A
【解析】
试题分析：考查连词。句意：游客中的大多数仅仅坐在树荫下就很幸福，因为这是一次火车上的长途且满是尘土等的旅行。for连接两个并列句，表示间接原因。根据题干中的a long, dusty journey和happy判断，故选A项。