We don’t know how to prevent the flu. Shall we ask Doctor Wang Hai for______?
He found very difficultthe math problem.
My sister has learnt English _________.
—Did Tom’s parents go to the meeting yesterday? —Yes,of them did, butspoke.
Kate doesn’t want to buy the skirt because ____the color ______ the size fits her.
--- Whose backpack is this? --- Itbe Mary’s. She is looking for hers.