I forget where I read the article, or I ______ it to you now.[ ]

He is one of the cleverest students ________ hard work was paid in the end.

I don’t agree _______ you and I don’t agree _______ take risks.

I really don’t know if she ________ it when she ________.

Einstein’s Theory of Relativity is so________ thatmost of us can not understand it.