35. No bread eaten by man is so sweet as ______earned by his own labor.

　 A. one　　 　　　　　B. those　　　 　　　　C. it　　　 　　　　D. that

34. You ________pay too much attention to your handwriting, as it is so important.

A. can't　　 　　　　　　B. shouldn't　　 　　　　C. mustn't　　 　　　D. needn't

33. When and why he came here ________ yet.

A. has not known　 　　　　　　　　　　　　　 　B. are not known 　

C. has not been known　 　　　　　　　　　 　D. have not been known