歌手赛琳娜·戈麦斯进行肾移植手术

chart – n. a list that shows which music recordings have sold the most during a recent period of time

lay low – v. to not go out in public very often, stay out of the spotlight

transplant – n. a medical operation in which an organ or other part is removed from the body of one person and put into the body of another person

immune system– n. the system that protects your body from diseases and infections

chemotherapy– n. the use of chemicals to treat a disease, like cancer