Waste paper shouldn’t _____ everywhere. It’s our duty to keep our classroom clean. A. be thrown B. throw C. is thrown
He can’t state clearly how long he has ___________ the bicycle?
----How can I improve(提高) my listening skills? -----_______________more.
--My aunt ______________ Singapore for a holiday. ---It’s a beautiful country. I ___________there twice.
Look! __________ high speed the roller coaster is __________.
What will the computer ______ in the future?