During the siege of paris in the franco-prussian war of the 1870s mail was sent from the capital by balloon along with hundreds of homing pigeons

During the siege of paris in the franco-prussian war of the 1870s mail was sent from the capital by balloon along with hundreds of homing pigeons by a balloon.

a. "to practice" is the best phrase to complete the sentence.

explanation:

during the summer, she likes to practice her soccer skills so that she is ready to play in the fall.

(note that : all the other options "the practicing of", "practice for" and "to do a practice on" are inappropriate as they make the sentence grammatically incorrect.)