He managed to reach the summit of his career, but it was at the ________ of his health.

Don’t leave matches or cigarettes on the table within      of little children. 

This new-type machine ____.

Her question was so difficult that I could hardly make any ____ of it at all.　 

We can’t afford such an expensive car. You know, our total _____ adds up to no more than $10,000 a year.