—_______ is this pen? —It’s mine.
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?