Somebody is knowcking on the door.

The person inside said,'Who is it?'
1. It's me, Tom.
2. This is me, Tom.
3. I'm me, Tom.
4. That's me, Tom.
5. It's me.
6. That's me.
7. This is me.
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In the situation, which expressions can we use among them?

The correct ones are 1, 2 (maybe), 5, and 7.

In this situation, the following expressions can be used:

1. It's me, Tom.
5. It's me.
6. That's me.
7. This is me.

Explanation:
When someone is knocking on the door and the person inside asks, "Who is it?" the typical response would be to identify oneself. You can use the expressions "It's me," "That's me," or "This is me" to answer the question and let the person inside know your identity. Adding your name, in this case "Tom," further clarifies who you are. So options 1, 5, 6, and 7 are appropriate responses in this situation. Options 2 and 3, while grammatically correct, don't sound as natural or commonly used in this context.