He asked a lot of questions, none of ______ was easy to answer.
It is difficult for any of us to eat better, exercise more and sleep enough _________ we know we should.
Hardly _______________ when we were told to stop.
The girl seldom, if _____, turned to her brother for protection.
She is such a lovely girl ____ is liked by everybody.
---Why don’t you use the knife? ---It needs ___________________.