On offshore drilling units，each EPIRB or SART must be tested once every（）.
A: Aday
B: Bweek
C: Cmonth
D: Dyear
A: Aday
B: Bweek
C: Cmonth
D: Dyear
举一反三
- GMDSS要求船舶必须配备（）. A: DSC和SES B: SART、TWO-WAY VHF和EPIRB C: SART、EPIRB和518NAVTEX D: SART、TWO-WAY VHF、EPIRB和518NAVTEX，VHF DSC
- An offshore drilling unit must be equipped with a first aid kit approved by the（）. A: Coast Guard B: American Bureau of Shipping C: Minerals Management Service D: Mine Safety and Health Administratio
- The Olympic Games are held once _________. A: every five years B: every four years C: every-four-year D: each four years
- A new theory ______ before it can be put into practice. A: must be tested B: be tested C: can be tested D: to be tested
- Every student must ______ himself at the beginning of each semester. A: sign B: enroll C: admit D: register