What is to blame is not only your inability to learn Micro-biology, but also your yearn to live up to the teacher´s expectations. When you have tried your best(or even not yet), you need to learn to say, sorry, but that´s the best I can do. Then quit, not only physically.
Dear malnu
Thank you very much.
Not only you gives me a support to fight against depression,but also helps me with my English.
I'm very worry about my CET6 on December 23th this year.
I can not review it because I consider that my English is poor .It is very difficult for me to take out my textbook and do some execise.
It is you arousing my enthusiasm for English!