Having a trip abroad is certainly good for the old couple, but it remains _____ whether they will enjoy it.
. It is only when you nearly lose someone ____________ you fully realize how much you value him.
--I'm going downtown.--Come on.
--Shall Mary come and play computer games?--No,__________ she has finished her homework.
-I'm sorry, I shouldn't have been so rude to you.--You___________ your temper but that's OK.
Whether ways will be found to stop pollution or not is just___________ worries the public.