wǒ / zhèng / zài / xué / xí / wēi / jī / fēn / zuì / jìn / zǒng / jué / de / jí / xiàn / bù / fen / hěn / nán我正在学习微积分,最近总觉得极限部分很难。I am studying calculus, and lately I have found the section on limits quite difficult.