Word Collocation

Which word completes each set of collocations or fixed phrases?

a) an instrument panel
a panel of experts
a control panel
a wooden panel

b) a secret ballot
a secret agent
keep it a secret
meet in secret
the secret of success

c) take stock of the situation
it's out of stock
the stock exchange
the stock market


d) a time sheet
a time zone
only time will tell
long time no see
for the time being


e) a child minder
child abuse
child care facilities
a child prodigy
behaving like a child