Sure，you’ve watched extreme pet sports on Animal Planet. But did you know that there’s a whole world of athletic activities for dogs right in our area?

There are some reasons for considering taking part in such activities. Such sports strengthen the close feelings between dog and owner，and also benefit your pup’s body and mind.“ Dogs that are tied with chains often have behavioral problems，” says Lee Morgan. “They love to go out and play as much as we do.”

Of course，many of these sports require some amount of practice，and some breeds are simply better at certain activities than others .But all dogs can participate in the following games.

Frisbee Dogs（投掷游戏用的）飞盘

This sport requires you to throw as many Frisbees as your dog can catch in a 60­second time period. The further out your dog catches the Frisbee，the more points you rack up. Extra points are awarded if your pet catches the Frisbee while it’s still in the air. Mid Atlantic Disc Dogs (MAD­Dogs) hosts local competitions and offers informal instruction in local parks or even in people’s backyards.

Flyball Dogs

The sport has been around since 1970s.Flyball is a relay race with four dogs in a team. Each must jump four hurdles (跨栏) spaced with 10 feet apart and then land on a spring­loaded box that shoots out a tennis ball. The dog must then catch the ball and run back over the four hurdles. Once that’s done，the next dog can go. The first team that successfully completes the course wins the competition. There are a number of local teams，including 4 Dog Night，which holds classes for beginners and intermediate players and is always looking for new team members. The Beltway Bandits is another team，based in Leesburg，that hosts private classes and competitions.

1.Dogs that are always tied with chains often have behavioral problems because ________.

2.We can infer that this passage is ________.

3.The second paragraph mainly talks about ________.

4.From Flyball Dogs，we know that ________.