--Do you know our town at all? ---No, this is the first time I ___ there.
Young people tend to get up very late unless ________ to rise early.
No reader ________ take away a book from the library without the permission of the librarian.
. --Did you see ________ may be the longest total solar eclipse (日全食)in 500 years yesterday? --No, it was cloudy above my city at that time.
________ a two-year period, Nancy became addicted to painkillers (止疼药).
. At noon in summer the villagers like to seek shade ________ the air is cooler.