to 부정사용법이 다른것?
1. my cousin is difficult to treat.
2. foreign language is hard to learn.
3. these dresses are easy to work in. (해석 부탁)
4. it is impossible to solve the puzzle.

his need to feed his army during a war led him ti invent canned food. ( 해석과 용법 부탁드립니다.)