The traditional view is ________ we sleep because our brain is “programmed” to make us do so.
.-I can smell something _____ in the kitchen. Can I call you back in a minute? - OK.
A middle-aged woman came ____to the bus stop, only ___ the bus had gone.
.- Can I smoke here? - Sorry. We don’t allow _____ here.
.It’s no _____ arguing with Bill because he will never change his mind.
- Robert is indeed a wise man. - Oh, yes. How often I have regretted _____ his advice!