While I _______ my bedroom, Joe called and said he wanted me to go boating with him.
| A．clean | B．am cleaning |
| C．have cleaned | D．was cleaning |
Many accidents ______ by careless drivers last year.
| A．are caused | B．were caused | C．have caused | D．will cause |
I will send you an e-mail as soon as I ______ in Canada.
| A．arrive | B．arrived | C．am arriving | D．will arrive |
--- What were you doing this time yesterday?
--- I ______ on the grass and drawing a picture.
| A．sit | B．sat | C．am sitting | D．was sitting |
My aunt is a writer. She ______ more than ten books since 1980.
| A．writes | B．wrote | C．has written | D．will write |
--- Excuse me, could you tell me how ______ to Beijing Zoo?
--- Well, you may take Bus No.27.
| A．get | B．gets | C．getting | D．to get |