sentences:  Four days later, she fired two torpedoes at the Japanese merchant ship "Koryo Maru No.2", but the torpedoes passed underneath the ship; the submarine surfaced and sank the vessel with her deck gun.On 7 February, the boat launched a landing party at Lem Hua Krung Yai, Siam, then torpedoed and sank the Japanese minelayer "Choko Maru" west of Malaya five days later.