从方框中选择适当的引导词填空,其中有三个词是多余的。 when, that, how, what, whose, if, why, whether 1. I don't know _____ he hasn't come yet. 2. Do you know _____ dictionary this is? 3. They don't know _____ you will do in a week. 4. She asked me _____ I wanted tea or coffee. 5. We know _____ he will work hard from now on.