Here are the Minnesota AP Member Exchange Features for July 28-30:

FOR SATURDAY-SUNDAY:

EXCHANGE-DEMOLITION DERBY PROMOTER

KASSON, Minn. — After more than two decades promoting demolition derbies at the Dodge County Fair and other area venues, a Minnesota demolition derby promoter is retiring from the sport. Three more derbies and Kasson promoter Mark Houston will be done. Houston's life has been steeped in the car culture, but he said he's now in the mood for less noisy pastimes. By Matthew Stolle, Post Bulletin. SENT IN ADVANCE: 663 words, photos.

EXCHANGE-THERAPY ANIMAL CLUB

ST. CLOUD, Minn. — A Minnesota therapy animal club is bringing a calming comfort to hospitals and schools. The Central Minnesota Therapy Animal Association consists of nearly two dozen people and their certified therapy pets. Their mission is to provide positive animal interactions to better people's health and improve lives. The group visits people of all ages in different settings. By Anna Haecherl, St. Cloud Times. SENT IN ADVANCE: 491 words, photos.

FOR MONDAY:

EXCHANGE-ALL-SEASON GREENHOUSES

LAKE CITY, Minn. — A Minnesota farmer is using greenhouses year-round. In the winter, Andrew Serio keeps his pair of greenhouses warm by using the sun's rays and in-floor heating circulated via tubes running through the cement. But in the summer, computer-controlled vents and fans, and swamp coolers help regulate and dissipate the heat, making his custom-built greenhouse a four-season growing space. By Brian Todd, Agri-News. SENT IN ADVANCE: 774 words, photos.

EXCHANGE-AMERICAN NINJA WARRIOR-STUDENT

MINNEAPOLIS — A University of Minnesota graduate student has been competing on the sports competition show "American Ninja Warrior." In between his coursework for his Ph.D. in entomology, Eric Middleton trains. He has been competing on the show for the past three seasons and has earned the moniker "The Human Dung Beetle" for his obsession with insects. By Amie Stager, Minnesota Daily. SENT IN ADVANCE: 503 words, photos.

The AP, Minneapolis