freeload       
verb [ I or T ]  disapproving uk/ˈfriːˌləʊd/ us/ˈfriːˌloʊd/
 占便宜,吃白食
to use money or other things provided by other people, and give nothing in return
  He had a reputation for freeloading off friends and acquaintances. 大家都知道他喜欢占朋友和熟人的便宜。 
 The restaurant is full of corporate executives and freeloading food critics. 饭馆里挤满了企业高管和吃白食的美食评论家。 
 - More examples
 - Who needs to earn their own living when you can freeload off an aged billionaire?
 - I freeloaded a few glasses of champagne at a charity event.
 - Those people need to pay some taxes. They are freeloading.
 - "I wasn't making a contribution to the organization," he says. "I was freeloading. I was collecting a paycheck and not earning it."
 - She left aside her own soap and shampoo in order to freeload a few squirts and squeezes of the gels, mousses and lotions provided by the hotel.