This little poem comes from Disticha de Educatione of Urbano Appendini, published in 1834; you can see the whole book at Google Books.
Natura Magistra
Quidquid agis, tibi naturam propone magistram;
Hanc sequere, hanc cura, gnarus ut assimiles.
The vocabulary is keyed to the DCC Latin Vocabulary list. There is only one word in this poem that is not on the DCC list:
assimilō, assimilāre: make similar, imitate
gnārus, -a, -um: knowledgeable, skilled, expert
agō agere ēgī āctum: drive, do, act
cūrō -āre: care for (+ acc.)
hic haec hoc: this; hōc: on this account
magister, magistrī m.: master, chief
nātūra -ae f.: nature
prōpōnō -pōnere -posuī -positum: put forth, propose, present
quisquis quidquid: whoever, whichever
sequor sequī secūtus sum: follow
tū tuī tibi tē: you (sing.)
ut, uti: as (+ indic.); so that, with the result that (+ subj.)
