2 A: What ___________ (you/have) for breakfast yesterday? B: A glass of milk and cereal.

Okay, let's fill in the blank with the correct form of the verb in the past simple tense.

1. A: What did you have for breakfast yesterday?

   B: A glass of milk and cereal.

Here's the explanation:

• To form a question in the past simple with the verb 'have', we use the auxiliary verb 'did' before the subject 'you', and the base form of the verb 'have'. Thus, it becomes "What did you have...?"