1. Who he cares about doesn't care about him.<br/><br/>2. She realized that who she works with is important to her.<br/><br/>3. She realized that who she loves has gone.<br/><br/>4. Who knows the rules best will win the game.<br/><br/>5. Who is regarded as great always has a humble heart.<br/><br/>Do the sentence make sense? I think 1, 3 do not make sense. What do you think? <br/><br/>Thanks in advance!