In hot summer, we should pay attention toprotecting ourselves _____ strong sunlight.

_____the night air was, we slept deeply because we were so tired after the long journey.

achieve a lot when we learn to let our differences unite , rather than _______ us.

Internet, as well as the telephones, ________ an important part in our daily life.

Jack Ripper was ________ for murdering many people in the nineteenth century.