"latter" (l.6) is a comparative of superiority.

teaching skills in isolation is not so rich as teaching them in an integrated way.

the integrated teaching/learning of the four skills provides the students with more motivation.

listening must be taught with speaking, whereas reading has to be taught together with writing.

the four skills should be taught separately.

"rarely" (l.14) is the same as seldom.

"them all" (l.11) refers to "meaning of a word" (l.10-11).

"along with" (l.1) means together with.

even when it comes to material objects, the one-to-one relation of words in two languages may raise arguments.

translation of words in different languages is a difficult task.