That was because the school bus was by a thick fog.A. broke offB. held upC. kept upD. tur

问题补充：

That was because the school bus was by a thick fog.

A. broke off

B. held up

C. kept up

D. turned off

答案：

A. broke off

(答案→)B. held up

C. kept up

D. turned off

解析：句意：那都是因为由于大雾校车被延误了。A. break off打断，终止C. keep up保持D. turn off 关掉电源等B. hold up 延误,阻挡，根据句意和动词短语的意思判断B最佳。

考点:考查动词短语的用法。