21.Which sports activities provide protective equipment free of charge?A.Bubble Football and Snowshoe Hiking.B.Indoor Epee Fencing and Snowshoe Hiking.C.Bubble Football and Kayak Rowing.D.Indoor Epee Fencing and Kayak Rowing.22.What is a special requirement for joining the summer sports class?A.Bring sunglasses.B.Pass a swimming test.C.Think fast and control yourself.D.Rent sports tools in advance.23.What do the four sports activities have in common?A.They take place outdoors all year round.B.They are designed to improve teamwork.C.They last two months in each single season.D.They accept students without any experience.