单项选择题
For the duties （）in one emergency, one person may do more than one job and one job may be done by more than one person.
A.assigning B.assign C.toassign D.assigned
单项选择题 Seven short blasts continued for one minute means （）.
单项选择题 Several sand boxes need （）.
单项选择题 When a ship is abandoned, all of the crew members hearing the alarm sounding should put on （）.
