It is good manners to eat up_______is left in your plate.
I lost my way in complete darkness and ,______ matter worse, it began to rain.
You can't work out this problem ___in this way.
I had no idea ____ is better, so I took ____ of them.
The headmaster hurried to the concert hall only ___ the speaker ____.
The thing that_____ is not whether you fail or not, but whether you try or not.