1 . My decision is________all of us are to start at 6 o'clock tomorrow morning. (用适当的词填空)

2 . He did not work hard and that’s ________ he failed the exam. (用适当的词填空)

3 . The woman was crying. That’s ________ her son was drowned in a river. (用适当的词填空)

4 . Mr White is opposed to repairing the old building, and that's ________ I don' 't agree. (用适当的词填空)

6 . This is ________ my father has taught me—to always face difficulties and hope for the best. (用适当的词填空)

7 . He overslept and got up too late this morning and that was ________ he missed the train.（用适当的词填空）

9 . But my teacher always says, “We want to be   younger.” so about the age of Western women, my advice is ______ if you don’t know it, don’t ask about it; if you really know it, don’t mention it. (用适当的词填空)