She goes to school every day _______ Sunday.
. We can hope ___ the best but we must prepare ____ the worst at the same time.
.Professor White has received a letter ___ to give a lecture in Peking University.
.The ____ in these villages has to get its water from well-spring.
—Where is your Chinese teacher from? —I’m not sure, but his Chinese ____ Hebei.
The birds flew ___ the direction of the south.