I guess I'd better tear up the letter and start over again.
我想我应该把信撕掉重新再写。
My home is in the capital.It's a cosmopolitan city.
我的家在首都.它是一个国际性的城市。
Some of the bigger firms are engaged in researches which are of such general and fundamental nature that it is a positive advantage to them not to keep them secret.