I often make some mistakes in work, serious or unserious, at first, my supervisor don't take it serious, just comforted me to forget it for we are human nature,  it was common to make something wrong. But working here for almost one year, many misteakes still can be found in my work, which make my supervisor doubt my work and not rest assured to assign me some work to do . Now my life here is very leisure, almost nothing to do for the whole day. To make things like this, i am wordless. I always ask myslef why I am so careless. To be honest, i want to finish my work without any mistakes-making, but undesireable. The more i think, the more mistakes i make. Not say my supervisor doubt my work, so do I, myslef. I am so sad now, not happy everyday. Actually, i work very hard, but not no positvie results. How can i do anything with care, and not so forgetful.