~だろうか (I wonder if)

What is this? If it's not a shady sales pitch, is it some new form of reverse pickup?

How could a university professor of all people end up committing murder?

Can newspapers survive?

Do ghosts really exist, I wonder.

If this plane were hijacked, what on earth would you do?

I wonder if she'll dare go into that forest.

I wonder if he enjoyed the last game.

I wonder if Apple's new laptop will be announced on schedule.

I wonder if I'll be able to see him next year.

I wonder if it will rain tomorrow.

I wonder what would happen if I failed.

Is that really true?

I wonder if she'll be able to finish it today.

I wonder what ever became of her.

I wonder what the temperature will be like tomorrow.