Lucy,could I use your computer?Sorry,I'm going to _____ now.

could I use your computer.Sorry,I'm going to______it now. ----Could I use your computer? ----Sorry,I'm going to ______ Could I use you computer?Sorry,I am going to work on it now. -Could I use your computer? could i use your book?i'm sorry but i( )use the book myself sorry,I haven;t finished your book _____ ,but I;m going to. --Hi,Jeff,can I use your computer?--I'm sorry,_____mine is n ---Ross,Can I use your computer to do my homework?---Sorry,I I'm sorry i am going to _____ to get to your house.为什么选带be的啊 Could I use your dictionary?—I’m sorry it isn’t -Could I use your dictionary?-Sorry,you_____.I'm using it. 请帮我填几个空1.-Could I use your computer?-Sorry,I am working ____