without doubt

副词 without doubt:

1. admittedly
   同义词：to be sure, no doubt
2. with certainty
   同义词：undoubtedly, doubtless, beyond question, beyond any doubt

1. He is without doubt the cleverest student I've ever taught.
   他确实是我所教过的学生中最聪明的。
2. He is, without doubt, the greatest golfer in Japan.
   毫无疑问的他是称霸日本的高尔夫球手。