His _____of the aeroplane was correct in every detail and could really fly.

In our hometown, a private school was closed down as a _______ of its terribly bad management.

Many kinds of birds fly south at the ______ of winter.

The members of the club wouldn't run a _____ in entrusting（委托） the organization to an unreliable person.

Joan has been missing for a couple of days and there is growing _____for her safety.