1. It is a good thing for you to have such a good chance to study abroad, but it remains _______ whether you can really learn something useful.

　　A. seen B. to see

　　C. to be seen D. seeing

　　2. With an examination _______, the students felt relaxed and enjoyed themselves the whole night.

　　A.to take B. being taken

　　C. taking D. taken

　　3. If you want to make even greater progress in your studies, you still have many difficulties__________.

　　A. to overcome B. to have overcome

　　C. overcoming D. overcome

　　4. He appreciated _______ the chance to deliver his thesis in the annual symposium on Comparative Literature.

　　A. having given B. to have been given

　　C. to have given D. having been given

　　5. An overloaded school bus carrying 65 pupils rushed into the river last Saturday, _______ 50 pupils dead and 15 injured.

　　A. left B. to leave

　　C. leaving D. being left