Humpback whales are sometimes called performers of the ocean．This is because they can make impressive movements when they dive．The name“humpback”，which is the common name for this whale，refers to the typical curve shape the whale’s back forms as it dives．
Sometimes the humpback will dive with a fantastic movement，known as a breach．During breaching the whale uses its powerful tail flukes to lift nearly two-thirds of its body out of the water in a giant leap．A breach might also include a sideways twist with fins stretched out like wings，as the whale reaches the height of the breach．
A humpback whale breathes air at the surface of the water through two blowholes which are located near the top of the head．It blows a double stream of water that can rise up to 4meters above the water．
The humpback has a small dorsal fin located towards the tail flukes about two-thirds of the way down its back．Other distinguishing features include large pectoral fins，which may be up to a third of the body length，and unique black and white spots on the underside of the tail flu
荆晓峰回答：
69．B 细节理解题．根据文章右栏中的Environment中的内容“From warm tropical （热带的） waters，where they breed，to cold polar waters，where they eat．”可知，humpbackwhale在热带水域繁殖，在寒带水域中觅食，故选B．
70．A 细节理解题．根据文章第二段中的内容“Sometimes the humpback will dive with a fantastic movement，known as a breach．During breaching the whale uses its powerful tail flukes to lift nearly two-thirds of its body out of the water in a giant leap”可知，有时驼背鲸在潜水时会有种意想不到的动作，称为“突破”．在“突破”时，座头鲸会用它强有力的尾巴将自己身体的三分之二在一个飞跃到水的外面，故选A．
71．A 细节理解题．根据文章第四段“The humpback has a small dorsal fin located towards the tail flukes about two-thirds of the way down its back．Other distinguishing features include large pectoral fins，which may be up to a third of the body length，and unique black and white spots on the underside of the tail flukes．These markings are like fingerprints：no two are the same．”可知，座头鲸有一个较小的背鳍，大概是背部三分之二靠近尾部的地方．它其他的特征还包括大的胸鳍，总长有全部身体的三分之一长，以及在尾鳍下方有一些特殊的黑与白的点．这些的特点有些像指纹那样．没有两条的驼背鲸有同样的标记．A项说法正确，B项错误；由第一段“The name“humpback”，which is the common name for this whale，refers to the typical curve shape the whale’s back forms as it dives”可知，起这个名字是因为当它要潜入水中时，会将背部提到一种典型的曲线形状，C项错误和“Humpback whales are sometimes called performers of the ocean”，驼背鲸有时称为海洋的表演者，D项说法错误，故选A．
