I heard that you really had a wonderful time at John's birthday party, _____?

We need a more capable leader, ______ with strong will and as well as good humour.

This robot is supposed to save a lot of labor, but it remains a problem if it ______.

Theprofessorcouldhardlyfindsufficientgrounds_____hisargumentsinfavorofthenewtheory.

______ that no one was ever prepared for it.