This is the book( ) I am looking for.A.it B./ C.what

This is the book( ) I am looking for.C.whatI am sorry Iam late because the bus broke (损坏）on the way.
Look!The table is being covered (被覆盖）beautiful cloth.
翻译：你曾听过韩红唱的那首歌吗?（hear of,which)Have you heard of the song sung by Han Hong?
请点击下面的“选为满意答案”按钮,
再问： 为什么Look!The table is being covered (被覆盖）beautiful cloth。是用is,它不是已经被覆盖了吗？ 为什么This is the book( ) I am looking for. C.whatI 可以解释一下吗？麻烦了。
再答： 因为table是单数，所以后面的系动词用is This is the book( ) I am looking for. 这道题选B，填that也可以，刚才选错了，对不起