kill two birds with one stone, do one task and finish two or more goals (literally, “one stone, two birds”)

top, peak, summit, vertex / (geometry, graph theory) vertex / (geometry) apex

(military) a corporal

a chief of a whole system / (in America) president of a university; (in Britain) chancellor of a university / secretary-general

tone of voice

early] morning

investigation, examination, inspection, inquiry, enquiry, survey

(military) a sergeant major / (military) a chief petty officer

birds, bird

satisfactory; favorable