As far as I know he is still working in Bristol.

=> To _______

Đáp án: To the best of my knowledge, he is still working in Bristol. 

Giải thích: As far as + S + know(s) = to the best of one’s knowledge: theo như ... biết

Dịch: Theo như tôi biết thì anh ấy vẫn đang làm việc ở Bristol.