Why are photos and videos of cats high-fiving suddenly popping up on social media？
Ask Jackson Galaxy， who launched Cat Pawsitive last year， a program that encourages animal shelters to teach cats how to do tricks to make them more attractive for adoption．
The idea is simple． A kitty that can sit on command or give a high five shows that it can listen to instructions and connect with others． A high five can make a shy cat open up， Galaxy said．
"Big life changes can lead to cats losing their confidence， and we help those cats to feel more confident and to feel safe interacting with new people．" Christie Rogero， program manager for Cat Pawsitive， said．
And Stephen Holdeman， training manager at the KC Pet Project， added： "All we need to train a cat to do tricks is the right amount of patience， timing and motivation．" He uses a technique called "operant conditioning （操作性条件反射）"， which associates a cat's action with getting a reward such as a favorite food or treat．
He also uses a clicker-a training device that makes a clicking noise． "In the initial stage， we get the cat used to the idea that when it hears the sound of the clicker， one of its favorite treats appears． After we have bridged these two ideas together we can use the clicker to reinforce different actions the cat does to let it know that if it repeats the action， it will get a treat．"
After several repetitions， the cat starts to link everything together． Now all you need to do is let your extended hand be the target， and we've got a high five．



According to the text， how can learning tricks benefit cats at animal shelters？ ______

A. It is a good way for shelters to raise money．
B. It allows them to pick up skills to stay safe．
C. It helps them interact more with each other．
D. It helps them build confidence and get adopted．

According to the text， what should be done from the start to train cats to learn tricks？ ______

A. Teaching them different actions．
B. Teaching them how to use a clicker．
C. Making them patient enough to repeat actions．
D. Helping them connect the sound of a clicker with treats．

What does the underlined word "reinforce" in paragraph 6 probably mean？ ______

A. record
B. strengthen
C. ignore
D. reward

What is the main purpose of the article？ ______

A. To explain how to train cats to perform tricks．
B. To show how cats are treated at animal shelters．
C. To describe the popularity of cats on social media．
D. To inform us of a program that trains cats to do tricks．