【推荐1】It____________(know) for a long time that Yellowstone was volcanic in nature that's what accounted for all its hot springs and other steamy features. (所给词的适当形式填空)

【推荐2】—Tom is in hospital now. He broke his arm.
—Oh, I ______________(not know). I will visit him this afternoon. (所给词的适当形式填空)

【推荐3】Even though we met for the first time, he talked as if we ________ (know) each other before. (所给词的适当形式填空)

【推荐1】I was caught in a heavy traffic jam; otherwise, I ________(keep) you waiting for such a long time. (所给词的适当形式填空)

【推荐2】If we_________   (book) a ticket earlier, we wouldn't be standing outside here hopelessly. (所给词的适当形式填空）

【推荐3】They ________ (win) the match if their captain _______ (not miss) that penalty. （所给词的适当形式填空）