George, the lonely tortoise, was said ________ on a tiny island of Pinta in 1971．

A．to have discovered

B．to have been discovered

C．having discovered

D．having been discovered

（）是指教师引导、组织儿童用集体讨论的方式，选择适当的节奏型以及合时的乐器，为儿童所熟悉的歌曲或乐曲设计伴奏的一种活动形式。