Choose the meaning of the given idiom

"To pick holes"

Find a word suitable for the expression "The style in which a writer makes a display of his knowledge".

My parents told me that I would have to ------- them when they become old. (Use appropriate phrasal verb from the following)

-------- money is invested by experienced investors who know about what they are doing.

A ----------- of gees was heard a mile away.

She has three children --------- her first husband.