On Sundays there were a lot of children playing in the park, _______ parents were seated together joking.
You had better _____ some time every day for sports so that you can keep yourself energetic.
---Obama took oath (宣誓)of office in the White House。 ---When was _____? ---____was on January 23,2013.
When changing lanes, a driver should use his turning signal to let other drivers know _________ .
China has been pushing the reform of public hospitals ______ all its citizens.
Everyone in the village is very friendly. It doesn’t matter ___ you have lived there for a short or a long time.