The chair is _____ wood.
—Simon,I wonder _______. —Last Saturday.
The factory ______ its waste into the river, but now it deals with the waste in a new way.
一Shall we go out for a trip to relax ourselves after the final exam?
—We need a new leader for our Helping Hands Club,but I don’t know_______.—Why not Mary? She is always willing to help others.
To improve his English,he spends _______one hour a day listening to English programmes.