The reason why he was late was ___he had taken a wrong bus.

When did your uncle arrive in China— He got to Guangzhou themorning of the 16th of April.

In the dark street, there wasn’t a single person _____ she could turn for help.

30. Only those who have experienced hardship ____ well aware of what happiness means.

The airline stewardess (空姐) said to passengers on ______ with a beautiful smile, “welcome _________!”