Is that _______ UFO in the sky(天空中)?
--- Can you sing this song in English? --- Yes, I ______.
—Where is your mother, Jack?—She is busy ____ a cake. I will have a birthday party tonight.
My mother often tells me __ to MP3 while I am doing my homework.
I think this room is ____ than yours.
—What is your favourite ____, Tom? —I like English best.