What time is your mother going to come back？

解答：

Your mother is going to come back at a specific time not mentioned.

Who will he see at the party？

解答：

He will see specific people at the party, but their names are not provided.

When are we going to have lunch？

解答：

We are going to have lunch at a specific time not mentioned.

How are you？

解答：

I am feeling good, thank you for asking.

What is that？

解答：

That is a specific item, but its name or nature is not provided.

这些句子使用了不同的特殊疑问词（如what, who, when, where, how）来引导疑问句，并提供了相应的解答。