READ OUT LOUD. Choose which marked text you prefer to practice with - macrons or accent marks - and read the text out loud until you feel comfortable and confident. Then, try reading the unmarked text at the bottom. It should be easy for you after practicing with the marked texts. :-)
MACRONS. Here is the text with macrons:
Alexander contemplātus imāginem suam, quam Apelles, celeberrimus pictor, pinxerat, minus laudāvit pictūram, quam ille expectāverat. Cum autem introductus equus adhinnīret equō pictō, quasi etiam hic vērus esset equus, tum Apelles: Ō rex (inquit), equus tuus artis pingendī perītior esse vidētur quam tū.
ACCENT MARKS. Here is the text with ecclesiastical accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Alexánder contemplátus imáginem suam, quam Apélles, celebérrimus pictor, pínxerat, minus laudávit pictúram, quam ille expectáverat. Cum autem introdúctus equus adhinníret equo picto, quasi etiam hic verus esset equus, tum Apélles: O rex (inquit), equus tuus artis pingéndi perítior esse vidétur quam tu.
UNMARKED TEXT. Here is the unmarked text - after practicing with the marked text that you prefer, you should not have any trouble with the unmarked text:
Alexander
contemplatus imaginem suam,
quam
Apelles, celeberrimus pictor,
pinxerat,
minus laudavit picturam,
quam ille expectaverat.
Cum autem introductus equus
adhinniret equo picto,
quasi etiam hic
verus esset equus,
tum Apelles:
O rex (inquit),
equus tuus
artis pingendi
peritior esse videtur
quam tu.
IMAGE. Here is an illustration for the story (image source) showing Alexander on horseback:
