The company had about 20 notebook computers but only one third _________ used regularly.Now we have sixty working all day long.
The traffic on the main streets has a longer green signal than __________ on the small ones.
Alice received an invitation from her boss,__________ came as a surprise.
Paper is __________ great Chinese contribution to human civilization.
Read this story,__________ you will realize that not everything can be bought with money.
It was __________ that we wanted to stay here for another two days.