八（1）班体育委员记录了每一小组七位同学定点投篮（每人投10个）的情况，投进篮筐的个数为：6，10，5，3，4，8，4。这组数据的中位数和极差分别是（   ）。

    Maui, one of the most beautiful islands in the world, is a dream place for a visit and there are so many attractions for you.

    HALEAKALA

    Mt. Haleakala is 10,023 feet high and is one of the two volcanoes that created this incredible Hawaiian island. Haleakala National Park offers a variety of activities, making it one of the most revisited attractions in all the Hawaiian Islands. The most popular activities include enjoying sunrise and sunset, hiking, and backcountry camping on Maui.

    ROAD TO HANA

    There are many ways to experience the Road to Hana, and the sleepy coastal Town of Hana, Maui. Visitors can go by group and private tours, or explore on their own by renting a vehicle. Beginning at the historic Town of Paia, visitors can enjoy decorated coastlines all the way to Hana, world-famous beaches in Hawaii, tropical landscapes, waterfal.ls, scenic lookout points, and cultural attractions that mark significant points in Maui's unique Hawaiian history.

    HO'OKIPA BEACH PARK

    Ho'okipa Beach Park is one of the most famous beaches in the world for professional surfing and windsurfing. In the ancient Hawaiian language, “ho'okipa” means hospitality, which is exactly what this Beach Park offers! At Ho'okipa, visitors can see the powerful coastline from the top parking lot for amazing photo opportunities. Or you can go to the sand for afternoon BBQ's and the glorious Maui sunshine.

    OHE'O GULCH POOLS

    The Ohe'o Gulch Pools, more commonly referred to as the Seven Sacred Pools, is a wonderful place to explore Maui on vacation. The lower pools are more easily accessed, and perhaps the best choice for visitors who want to jump in. Due to the popularity of the Seven Sacred Pools, it is highly suggested to arrive early for a chance to enjoy privacy in this beautiful location.

阅读下列三篇短文，按要求完成后面提出的问题。

A．蝙蝠在黑暗中能自由地飞翔，用蜡封住其耳朵，虽然把它放在明亮的房间里，仍像喝醉酒一样，一次次地碰到障碍物。后来，物理学家证实了蝙蝠能发出  ①  波，靠这种波的回声来确定目标和距离。

B．如果把八只同样的玻璃杯盛不同深度的水，再用一根细棒依次敲打杯子，可以发现声音的   ②   和水量有关。如果调节适当，可演奏出简单的曲谱，由此我们不难知道古代“编钟”的原理。

C．许多年前，“马可波罗”号帆船在“火地岛”失踪。科学家经过多年的研究，揭开了“马可波罗”号帆船上人们的“死亡之谜”：他们都是死于“亚声”。这是一种人耳听不到的声波，频率低于20 Hz 。当声波的频率在2 ~ 10 Hz时，人会产生恐惧、恶心、头晕等症状，其中5 Hz的声波对人危害最大，这是因为此时人的内脏的固有频率和“亚声”的频率极为相似，会形成内脏的共振，严重时，把内脏振坏而使人丧生。