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Actually we know he cannot personally reply each one. In time motion study terms, it is impossible. Never mind. It is good that he gives you an avenue to express your questions. His officers (base layer/higher layers 1&2&3 &etc.. if it concerns a particular ministry then it will be directed to them accordingly and their base layer/higher layers 1&2&3 &etc ) will draft and vet the reply. Serious matters will be highlighted to him.
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If 3 million of the SG population each ask you a question, are you sure you are free to personally answer each one?
If so, then how to cope?
Or you can have a group of officers to draft answers on your behalf. These drafts will be vetted by another one or two or three layers of successively higher ranking officers.
Presume that the questions will first be sorted into:
antagonistic
neutral
favourable
But there will be a few specially selected questions where you can give a favourable reply and these will be personally replied by you.
That will give impression that all were personally drafted and replied.
Have read elsewhere that at least one US President does not personally answer ALL his mail from US citizens.