Where is my pen ? Have you seen ____?— Oh, sorry. I have taken ____ by mistake.

f they are on sale, these air-conditionersare equal in price to , if not more expensive than , ______ , at the otherstore

The steel works in which David has worked for five years us with raw material in large quantities in the past two years. [ ]

China, ____ one of the great four countries with ancient civilizations, is best-known _______ its great development in all the fields over the years.

She sings very well, because she has a good ________ .