单项选择题
A.ship products survey
B.notarization survey
C.ship safety inspection
D.counseling service and publishing ship name list
单项选择题 If some surveys refer to statutory survey and ship classification survey but occur temporarily, we call them （）
单项选择题 Medium survey should be carried out （） times during the valid period of the certificate.
单项选择题 The first survey has two situations, one is changing （） survey, the another is making survey.