. The young ______ the vital forces in our society.
In autumn, _________ the weather is often cool and fine, people living in the city always like climbing hills for outdoor activities to strengthen their health.
—I telephoned him twice and I couldn’t get through to him. —The line might have been out of order, _________?
The USA has a quarter of the leading 200 in the latest ranking of the world universities, _________ 30 of the universities are in the UK.
Our school appeals to the students to _________ at least an hour every day to take exercise in order to raise learning efficiency.
Some of the members demanded to know why they had been kept _________ the true facts until they reached the present critical stage.