1.错.改正：She said sheˊd rather you would come tomorrow instead of today.
2.错.改正：The number of the audience,as we had expected,was well over one thousand.
3.错.改正：That mathematics is one of the most useful and fascinating divisions of human knowledge is widely accepted.
4.错.改正：The prices of fruits have risen recently however the prices of vegetables have gone down.
5.错.改正：Susan must have done quite well in the exam since she seems to be confident of passing it.