Since offshore oil drilling platforms, submarines and other super large cargoes have appeared one after another, semi-submersible ships have gradually found their place of use. Semi-submersible ships can use both unique sinking and floating methods and ro-ro with the help of terminal facilities. Various methods such as skid-mounting and hoisting have strong flexibility and convenience. In addition, most of the semi-submersible ships have self-propelled ability and the speed can reach more than 15 knots, which can greatly shorten the transportation cycle of important equipment. At the same time, due to its own With less equipment and less fuel consumption, the semi-submersible ship can reach tens of thousands of kilometers. More importantly, the semi-submersible ship sails in the water through the semi-submersible method, the draft is deep, and the deck is often consistent with the water surface, thus resisting high winds Is extremely stable. According to this text, is the following statement correct? ['Semi-submersible vessels can only load cargo by sinking and floating.', 'The main disadvantage of semi-submersibles is the relatively slow speed.', 'The semi-submersible ship is more stable due to the deeper draught when sailing.', 'Semi-submersibles only appeared after the emergence of very large cargo.']