If one or more blades （叶片） are missing make an entry in the engine logbook 如果一个或多个叶片丢失，请在发动机日志簿中进行记录
A.if one or more blades are broken, make an entry in the engine logbook B.if one or more blades are in place, make an entry in the engine logbook C.if one or more blades are absent, make an entry in the engine logbook正确答案C
