He ……. (teach) in this college for five years.teachesis teachingtaughthas been teaching

The correct form to fill in the blank is "has been teaching."

Explanation:

1. Context: The sentence refers to an action that started in the past and is still ongoing or relevant in the present.

2. Tense: The present perfect continuous tense ("has been teaching") is used here, as it emphasizes the duration of the action (teaching) up to now.

3. Other Options:

   • "teach" (base form) is incorrect in this context.
   • "teaches" (simple present) doesn't convey the duration.
   • "taught" (past tense) suggests the action is completed, which does not fit the context.

Therefore, the complete sentence is: "He has been teaching in this college for five years."