阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
A
UC Berkeley Youth Recreation Summer Camps
UC Berkeley Youth Recreation will provide a wide variety of one-week outdoor experiences and activities for the youth on summer camps 2023. Here are four best summer camps.
Windsurfing Camp
This camp is designed to teach students the basics of windsurfing, including balance and self-rescues. Through a combination of classroom instruction, demonstration and water time, campers are able to master the basics of the sport. A comfort with wind and water is strongly encouraged. Campers must be ages 10-17 to register. All campers must be able to swim and weigh 100 pounds or more to safely use public windsurfing equipment.
Price:$330. Those who have participated before can receive 10% off.
Sailing Camp
Campers learn and review the essentials of sailing at their experience level on the beautiful San Francisco Bay! 2023 brings exciting updates to the camp and helps sailors master new skills. Previous sailing experience is required. Campers must be ages 12-18 to register. All campers must have basic swimming skills.
Price:$255.
Skateboarding Camp
In this camp, skateboarders will learn mechanics and basic riding skills such as balance, riding switches, and dropping-in. Skaters will be assessed on the first day of the session and the lessons will be adapted to their ability. All participants are educated in skateboard safety. Campers must be ages 8-16 to register．Participants must bring their own skateboard，helmet and knee＆elbow pads（护具）.
Price:$300. $240 per person for group registration.
Rock Climbing Camp
Learn climbing skills，knot-tying，top-rope climbing and equipment care. Sites include Strawberry Canyon, Remillard, Indian Rock and Cragmont Parks. Campers must be ages 9-15 to register. All campers can enjoy the bus service to and from the campsites.
Price:$275.
21. What common skill is required for the participants of Windsurfing Camp and Sailing Camp?
A. Previous learning experience. B. Swimming
C. First aid knowledge.. D. Personal protective equipment.
22. What is special about Skateboarding Camp?
A. It is intended for primary pupils.
B. It'll issue certificates of excellence.
C. It gives a 10% discount for group registration.
D. It bases its lessons on campers’ levels.
23. Which camp offers public transportation for camp-goers?
A. Windsurfing Camp. B. Sailing Camp.
C. Rock Climbing Camp. D.Skateboarding Camp.
