用方框中所给单词或词组的适当填空，每词限用一次。

manage     miss    reason   on one’s own  knowledge

In the film Dearest, the busy parents set out to find their___________ son.
The_________ why a great man is great is that he resolves to be a great man.
I was able to finish the job ___________.
The club will hold a competition to test their members’ computer ____________.
In a busy world, __________ your time is increasingly important