He was a(n) ___________singer until the age of 40, when he turned professional.

.In our school, there is a rule that anyone shouldn’t play computer games during the ______ working time.

(2014·石家庄高中复习教学质检)I always try to be________to others when walking my pet dog along a pavement and step to the side with my dog to let them pass by.

Mary is always ready to do some __ work at the local geracomium（敬老院）in her spare time.

—Have you seen my pen bought during my visit to Hong Kong Disneyland?—Oh, Jane must have taken it _________ ; she has the same one as yours.