profitability

(historical) the "three talents": sky (天), earth (地) and people (人) (one who knows all three well would be an all-rounded person) / (figuratively) everything in the universe; all of creation

edible greens of the sort that naturally grows on mountains

mountain stronghold / mountain camp / shanzhai: imitation or counterfeit consumer goods, especially from China

three years of age, three years old

the sky

something empty / ineffectual / false

by heart, from memory, by rote

empty; vain; sky

(dialect) so; such