 Complete the following phrase:  On 7 December 1941, I-121 laid forty-two Type 88 Mark 1 mines northeast of Singapore in the vicinity of . She then took up her patrol station off the eastern entrance of Johore Strait. In East Asia, World War II began on 8 December 1941, and Japanese forces invaded British Malaya to the north of Singapore that day. Reassigned to the Southern Submarine Force, she called at Cam Ranh Bay in Japanese-occupied French Indochina on 12 December 1941, then got back underway the same day to support the 