I tried phoning her office, but I couldn’t _____.

Only when he met the girl his aunt introduced to him ____ that he had seen her before. [ ]

The video often reminds me the days when I worked on the farm my classmates.

_____ the city’s public school system should be opento the children of migrant workers has become the focus of discussion.

illing in Antarctica dragged on slowly becauseof lack of money, equipment breakdowns, environmental ______ and severe cold.