To test the quality of its books, a printing press randomly picks a book from its press and then selects every twentieth book off the press for a half hour. Which sampling method is used?

A. lottery method

B. random number table

C. stratified random sampling

D. systematic random sampling

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.