不省,应该说：I agree with （what )you said
①I think the coolest thing is sunglasses.对请说明一下理由1.agree with 后面如果接由连接代词what, which who 等引导的从句时，with 不省。英语中只有在介词接that-从句时要省介词的。如：insist on doing sthinsist that-从句reply to sb/ sthreply that-从句2. 虽不可以用单数代词it, one代类似sunglasses shoes trousers一类的东西， 但用名词the coolest thing 指代还是可以的。