JA says:

Mr. Wickham was therefore at leisure to talk to Elizabeth, and she was very willing to hear him, though what she chiefly wished to hear she could not hope to be told -- the history of his acquaintance with Mr. Darcy. She dared not even mention that gentleman. Her curiosity, however, was unexpectedly relieved. Mr. Wickham began the subject himself. He inquired how far Netherfield was from Meryton; and after receiving her answer, asked in an hesitating manner how long Mr. Darcy had been staying there.

I was thinking of why Wickham singled Lizzy for his inquiries about Darcy? Is she the only one of the party who noticed his greeting to Darcy,and he noticed that? or did he notice from Darcy's eyes that he cares about her and tries to take her in his side as soon as possible before Darcy does so.Also I wonder why Lizzy is so curiose to hear about Mr. Darcy from him. I think inside her heart she cares about Darcy more than W whom she knew for a very short time.