Answer:
He was on an underwater Expedition.
Step-by-step explanation:
The tense of a verb specifies the time at which the action occurs. English has three main tenses: the present, the past, and the future.
The three tenses for the line "He's on an undersea expedition" are as follows:
- He is now on an underwater expedition. The verb "is"
- He was on an underwater expedition in the past. The verb "was"
- He will be on an underwater expedition in the future. be a verb "will"