I'm glad you think so. 我很高兴你能那么想。

　　I thought so, too, but she didn't want to see me. 我也那么认为，不过她不愿意见我。

　　I think we should go. Don't you think so? 我觉得我们应该走了，你是不是这样想？

　　Dave might have the key.  大卫可能有钥匙。

　　I don't think so because he wasn't in yesterday.  我不那么认为，因为他昨天没有上班。