单句改错 （每句均有一处错误）。 1. I have arrived here for three days. 2. Look!The boys are visitting the Great Wall. 3. It's very important learn English well. 4. How do you think of the city? 5. I've heard the newest news. 6. I have caught these fish for about an hour. 7. I've found my pen. I forgot it on the desk. 8. I've never seen such an animal somewhere.  9. Have you finished to read all these newspapers and magazines? 10. Have they tried to send informations to us? ______ ______ ______ ______ ______ ______ ______ ______ ______ ______