VOA慢速英语:新冠病毒患者争相加入基列药物研究

enroll – v. to join or to take part in something

symptom – n. a change in the body or mind which indicates that a disease is present

anxiety – n. fear or nervousness about what may happen

rigorous – adj. doing something with a lot of interest and strength

placebo– n. a pill or substance that is given to a patient like a drug but that has no physical effect on the patient