Herman Melville, the writer of the famous whale story Moby Dick, wrote that humpback whales were “the most light-hearted of all the whales.” They swim in ocean areas close to land and are active at the surface, often jumping out of the water and coming down with a great splash. They are intelligent animals and can be seen working together as they hunt (58)_____ of small fish. And, if you listen closely, you might even hear one (59)_____. Marine biologist Jim Darling has studied the songs of humpback whales for 25 years. Darling says that only male humpbacks sing, but for (60)_____reasons. It was previously thought that they sang to attract females, but scientists showed this was incorrect. When they played recordings of whale songs in the ocean and no females came(61)_____. In addition to their long and mysterious songs, humpbacks make a(n) (62)_____of other sounds as they interact each day. When alarmed by enemies such as killer whales, or when the feeding is especially good, the sounds they produce can be louder than an airplane engine. 58. A. schools: bầy đàn B. swarms C. herds D. flocks 59. A. to sing B. singing C. be singing D. sung 60. A. secrete B. unshared C. unconscious`` D. unknown 61. A. into B. around C. up with D. on 62. A. amount B. great deal C. variety D. large sum