Convert each sentence from active to passive voice or from passive to active, and note the differences in emphasis these changes make. Example:
The surfers were informed by the lifeguard of a shark sighting.
The cartoonist sketched a picture of Sam with huge ears and a pointy chin.
The baby kangaroo is protected, fed, and taught how to survive by its mother.
The gifts were given out to the children by volunteers dressed as elves.
A new advertising company was chosen by the board members.