The passengers were in the traffic congestion which resulted from the accident ahead.
A. held out
B. held back
C. held up
D. held on
网友回答
A. held out
B. held back
(答案→)C. held up
D. held on
解析：句意：乘客由于前面的交通被阻挡在路上。hold out坚持；hold back隐瞒； hold up阻隔，阻挡；hold on继续。根据句意故选C。