Answer:
A simple lifestyle is led by them. - The verb "led" is in the passive voice form.
The buckets are being filled with water by the boy. - The verb "filled" is in the passive voice form, and the sentence starts with the object "buckets" instead of the subject "boy."
The broken shoe was mended by her. - The verb "mended" is in the passive voice form, and the sentence starts with the object "shoe" instead of the subject "she."
His grandfather has been taken to the doctor by him. - The verb "taken" is in the passive voice form, and the sentence starts with the object "grandfather" instead of the subject "he."
Lunch will be prepared for the children before their parents arrive. - The verb "prepared" is in the passive voice form, and the sentence starts with the object "lunch" instead of the subject "someone."