1.答案：B.
翻译：你干什么或你去哪里,这对我来说都不要紧/不重要/没有关系.（即我不在乎你做什么或去哪里）.
此题考查固定句型和形式主语的用法.
it为形式主语,真正的主语为后面的用or并列的两个主语从句what you do or where you go.
而this是不能充当句子的形式主语的.
且：It doesn't matter to me what you do or where you go.
= What you do or where you go doesn't matter to me.
= It makes no difference（makes no difference也可以说成doesn't make a/any difference） to me what you do or where you go.
= What you do or where you go makes no difference to me.
2.Word came that he had won the first prize.
此句必须使用that,而不能使用which.
此句的word为句子的主语,等同于news,意思是“消息”,且用在此次时,其前面不能加冠词.
而came是句子的谓语,后面的that he had won the first prize是同位语从句,对该句主语word的具体内容进行进一步的补充说明/解释.
如果用which去引导定语从句的话,则从句he had won the first prize和先行词word/news无法连接,而且该从句也不缺少word/news这样的名词性成分.