As a teacher anonymously noted, the textbooks had not been checked for several years and are often shared by students, so it is difficult to know who marked them.
Gẹ́gẹ́ bí olùkọ́ kan tí kò dárúkọ araa rẹ̀ ṣe sọ, wọn kò yẹ àwọn ìwé ìkọ́ni wọ̀nyí wò fún àìmọye ọdún, àwọn akẹ́kọ̀ọ́ sì máa ń pín in lò ni, fún ìdí èyí ó nira láti mọ ẹni tí ó kọ nǹkan sí i ní pàtó.