A.prevent chain from clinging to the wildcat B.clean the marine debris from the chain C.flake chain from a boat's chain locker D.clean chain prior to an x-ray inspection
A.經(jīng)濟B.安全C.發(fā)展D.主權(quán)
A.19世紀末B.20世紀末C.20世紀前半期D.19世紀前半期