【正文】
9. It’s too difficult _________(understand)what you are trying __________(say). 10. He could see the smoke ______________(rise) from the chimney (煙囪 )when he ______(walk) past your house at this time yesterday. 。 11. Our teacher is [ A. Too bad B. Very good C. Thanks a lot D. I’m sorry to hear it. 12. I think that it’s important _____ good health. A. keeping