A、it is A mEtAl towEr EquippED with Drilling mAChinEry.
B、it is A FloAting ship For thosE FishErmEn working on thE sEA、
C、it is A mAChinE thAt CAn Cut holEs DEEp Down in thE groun
D、
D、it is A movABlE FACtory thAt rEFinEs CruDE oil on thE spot.