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:
Dēmādes ōrātor, cum Athēnīs ōlim contiōnem habēret, nec eum cīvēs animīs attentīs audīrent, sed potius, ut Aesōpicam aliquam fābellam narrāret, ēnixē rogārent, ita demum exorsus est: Cerēs, Hirundo, et Anguilla iter ūnā faciēbant. Cum vērō ad quemdam fluvium pervēnissent, Hirundo quidem supervolāvit, Anguilla amnem subiit... Tum ipsīs, quid Cerēs ēgisset, interrogantibus, vōbīs, inquit, vehementer illa succēnsuit, quod, reī pūblicae cūrīs neglectīs, Aesōpicam fābulam lubentius audiātis.
ACCENT MARKS. Here is the text with accent marks, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Demádes orátor, cum Athénis olim contiónem habéret, nec eum cives ánimis atténtis audírent, sed pótius, ut Aesópicam áliquam fabéllam narráret, eníxe rogárent, ita demum exórsus est: Ceres, Hirúndo, et Anguílla iter una faciébant. Cum vero ad quemdam flúvium perveníssent, Hirúndo quidem supervolávit, Anguílla amnem súbiit... Tum ipsis, quid Ceres egísset, interrogántibus, vobis, inquit, veheménter illa succénsuit, quod, rei públicae curis negléctis, Aesópicam fábulam lubéntius audiátis.
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:
Demades orator,
cum
Athenis olim
contionem haberet,
nec eum
cives
animis attentis audirent,
sed potius,
ut
Aesopicam aliquam fabellam
narraret,
enixe rogarent,
ita demum exorsus est:
Ceres, Hirundo, et Anguilla
iter una faciebant.
Cum vero
ad quemdam fluvium
pervenissent,
Hirundo quidem supervolavit,
Anguilla amnem subiit...
Tum ipsis,
quid Ceres egisset,
interrogantibus,
vobis, inquit,
vehementer illa succensuit,
quod,
rei publicae curis neglectis,
Aesopicam fabulam
lubentius audiatis.
IMAGE. Here is an illustration for the story (image source) - it's an old Soviet postage stamp showing a painting of Ceres by Rubens:
