单项选择题
Statutory survey could be divided into two kinds, they are （）
A.first survey and certificate exchange survey B.first survey and operation survey C.first survey and periodic survey D.classification survey and certificate exchange survey
单项选择题 （）is not the main function of CCS.
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.
