jiào yòng > nán 
mùlù
No. 1
   nán
  nányǐ
  1. néng
yīngwénjièshì
  1. n.:  take a lot of,  difficult to,  cannot well
  2. v.:  hard to (predict, imagine, etc.)
  3. adj.:  find it difficult
fǎwénjièshì
  1. adj.  difficile à