'Sir, you forget I have given no answer. Accept my thanks for the compliment you are paying me, but it is impossible for me to accept your proposal.'

解析:proposal 求婚;提议
eg: She repulsed his proposal.

'Of course I understand,' said Mr Collins, 'that young ladies often do not accept a proposal of marriage the first time. I am therefore not at all discouraged, and sincerely hope we shall be married soon.'

解析:therefore 因此、所以
eg: He had few months to live,therefore he gave away all his money to charities.

sincerely 真诚地、由衷地、诚恳地
eg: I sincerely wish this Business Summit a complete success.

'Sir,' cried Elizabeth, 'your hope is rather extraordinary after what I've said! I am perfectly serious. You could not make me happy, and I'm convinced I'm the last woman in the world who would make you happy. And I'm sure that if Lady Catherine knew me,she would find me poorly qualified for the situation.'

解析:extraordinary 非凡的、特别的、不寻常的
eg: It is the most extraodinary experience ever happened in my life.

'If I knew Lady Catherine thought so―' began Mr Collins, looking very worried. 'But I cannot imagine she would disapprove of you. And when I have the honour of seeing her again, I shall certainly tell her how modest, economical and practical you are.'