The boys stopped and ________ digging holes to plant the trees.
A.set off B.set out
C.set about D.set up
The boys stopped and ________ digging holes to plant the trees.
A.set off B.set out
C.set about D.set up
C set off “出发,动身”;set out to do sth.“开始做某事”;set about doing sth.“着手做某事”;set up“设置,创立”。根据digging holes可知应该选用set about。