VOA慢速英语:比尔盖茨出资1亿美元对抗老年痴呆症

dementia - n. a mental illness that causes someone to be unable to think clearly or to understand what is real and what is not real

fund - n. an amount of money that is used for a special purpose

start-up - adj. a new business

charitable - adj. done or designed to help people who are poor, sick, etc.

scale - n. the size or level of something especially in comparison to something else

capacity - n. the ability to do something : a mental, emotional, or physical ability

gradual - adj. happening in a slow way over a long period of time