Where do the sun’s rays hit earth’s surface nearly at right angles?

The Sun's rays hit Earth's surface nearly at righ angles at Equator.

Duirng March equinox and September equinox the rays fall perpendicular at Equator. During this times the duration of day light and night are nearly equal.

The Sun's rays fall perpedicular during that time because the Sun is in the sky directly over the Equator.

 

Parenchyma, in plants, tissue typically composed of living cells that are thin-walled, unspecialized in structure, and therefore adaptable, with differentiation, to various functions.

this is what I understood! the word you wrote went above my mind XD and it actually doesn't mean anything ^_^ so maybe that was autocorrection!!

hope that helps uhh :)