Choose the right forms of the verb to complete the sentences.

The sentence is "I ______ Mary's address. Where does she live?" This implies a past action of forgetting. The correct past participle of 'forget' is 'forgotten'. Therefore, the sentence should be "I forgot Mary's address. Where does she live?" or "I have forgotten Mary's address. Where does she live?" Based on the options, 'forgot' is the simple past tense, and 'forgotten' is the past participle. The sentence structure suggests a simple past action or a present perfect action. Given the options, 'forgot' is the most appropriate simple past tense verb to fill the blank if the intention is to state that the speaker no longer remembers the address. If the intention is to emphasize the current state of not remembering due to a past event, 'have forgotten' would be used. However, the sentence is presented as a statement of fact about the past. The options provided are 'forgotten', 'forgot', and 'did forgot'. 'Did forgot' is grammatically incorrect. Between 'forgot' and 'forgotten', 'forgot' is the simple past tense, and 'forgotten' is the past participle. For a simple past statement, 'forgot' is correct. For a present perfect tense, 'have forgotten' would be used. The sentence "I ______ Mary's address." is a simple statement. The most direct and common way to express this is using the simple past tense. Therefore, 'forgot' is the correct choice.