.Having a trip abroad is certainly good for the old couple, but it remains ___ whether they will enjoy it.
His success in his career was due to his determination __________ what seemed impossible.
You can get the best result ________ you carry out the experiment under the desired conditions.
---You’ve finished off two pizzas! ---Yes. But the second is ___________ little bit small, so may I have __________ third one?
The officer insisted the young girl______a thief and ordered she______free.
I have to see the doctor because I a lot lately.