Why are you so anxious? It isn't your problem __________.
My brother likes eating very much but he isn't very _____ about the food he eats.
I just managed to _____ a quick breath before I was sucked under the water by the passing boat.
John says that his present job does not provide him with enough _____ for his organizing ability.
The meeting was _____ when the chairman fell ill.
The members of the club wouldn't run a _____ in entrusting(委托) the organization to an unreliable person.