英语翻译we are taught that a business letter should be written i

英语翻译
we are taught that a business letter should be written in a formal style rather than in a personal one .
it takes a long time to go there by train .it's quicker by road .
John plays football as well as ,if not better than ,David .
are you going to the concert no the tickets are (far too expensive )for us .这句中扩号里的词组还有如下三个选项,这三个选项为什么不能用?
terribly expensive
so much expensive
highly expensive