As far as we know, half of Canadian teenagers do not get enough sleep on school nights, _____?

—Does Bob have vegetables for dinner?—______. But his sister has some carrots.

It was Alice and her husband who sent the old man to the hospital , _______ ? 

- Didn't the robot have a rest?-_______. Because it never gets tired.

“Where _______ go to work？” “Where _______ go to work is not known.”