—Which of those electronic dictionaries do you like most? —        . They are both expensive and of little use.

______ we know, the air quality in the city has improved over the past two years.

On my desk is a photo that my father took of________when I was a baby. 

Those who smoke heavily should remind ________ of health, the bad smell and the feelings of other people.

   After graduation in 1997, he took _____degree in Florida .