gravely

副词 gravely:

1. in a grave and sober manner
   同义词：soberly, staidly
2. to a severe or serious degree
   同义词：badly, severely, seriously

1. If you think that, you are gravely mistaken.
   你若是那样想，就大错特错了。
2. Information confirm gravely advice possible countermeasure.
   已确认消息极为不好，请电告有何良策。