Hacker Exercise Experience

As an international student, Diane Hacker site is a good exercise for me to reinforce my foundation of grammar. I learnt a lot from it.
Since Chinese is my first language, I still can not avoid thinking about Chinese first, then translate it into English which may cause some grammar faults. The exercise helped me solve such kind of problems. For example,  E-ex 12-1,  It should be " Not all thin people are anorexic" instead of  "All thin people are not anorexic". The latter one is what is spoken in Chinese way.
The other one is mixed constructions exercise which taught me how to avoid using some words that are meaningless and rearrange the sentences in a proper way.
Another one is Parallelism exercise,  this part helped me know when to add  preposition correctly. I often forget to add preposition when I write a sentence which makes the sentence incomplete and hard to understand.
In a word, it is a nice exercise for learning and reinforcing.