Hi,
"Recently the number of deaths has been increasing drastically and TV has been emphasizing them".
I am a bit curious about the words 'has been' here.
You strictly reckon the words ' the number of deaths' as a singular unit. In a sense, yes, but I prefer to look at it that the subject is the singular word 'number'.
It will not be wrong to reckon as a plural unit too. I understand your thinking, but 'have' sounds incorrect here to me.
Best wishes, Clive