Scientists have d_____ that this disease is carried by mice.

discoverd

discover: [ dis'kʌvə ]
v. 发现

Examples:
1. She discovered the joy of writing.
她感到了写作的乐趣。
2. Columbus is said to have discovered America in 1492.
据说哥伦布于1492年发现了美洲。

Scientists have design that this disease is carried by mice 科学让有个构想让老鼠携带病源体

discovered
科学家已经发现这种疾病的病毒是由老鼠携带的。