都是对的
但是it was the news that mary gave me 强掉的是NEWS .that mary gave me 只是做个附带的说明,it was mary who gave me the news强调的是mary.
你可以把两句that 和who 后边的都省掉看看意思有什么不同就知道了：
it was news
it was mary
上边两句是说话人核心的意思.