题目

不等式||>的解集是(    )A.(-2,0)             B.(-2,0]             C.(-∞,-2)∪(0,+∞)          D.R 答案:答案:A【解析】由<0可得x∈(-2,0).阅读下列短文,从所给的四个选项中,选出最佳选项。CEvery small child knows the panic of losing sight of its mother in the supermarket, and as these delightful pictures show, small whales obviously feel the same way.Taken by a British diver who was following the sperm whale(抹香鲸) calf, they show the minute the baby - who had lost track of its mum-found her again in the sea off the Azores.Soaring 30ft across the waves, the newborn slammed(猛力推)its body onto the water with joy after becoming separated from its family group in the chilly(寒冷的)waters.But the whale calf was doing more than just jumping for joy.British biologist and dive guide Justin Hart, 44, who took the pictures, says that young whales communicate with older ones in the ocean by creating a slamming sound which travels through the water to the ears of the adults deep below.By leaping out of the water and slamming its 12ft long body onto the surface of the sea up to 30 times, the baby whale is telling its relatives where it is so they can regroup.He said: “We had been following the sperm whale calf for most of the day. Sperm whales, of all the whales and dolphins, are the species that dive the deepest and for the longest time.”“The calves have to follow what’s going on below them from the surface as best they can probably listening to the echo location(回声定位)clicks of the adults.”“However, sometimes the adults re-surface far out of sight of the calf, and in this situation the whales often leap out of the water causing a large bang as their bodies hit the surface. In this way, the whale family could regroup.”He added: “When I took the photo, two adults’ females had just resurfaced and the calf quite literally began jumping for joy.”Mr. Hart captured the rare image four miles from the port of Lajes do Pico while he was working as a crewman on an underwater documentary with special license to film sperm whales in the area.Sperm whales live in nearly all the world's oceans in groups of about 15 to 20 animals and they practice communal(集体的) childcare. The calves do not have to follow their mother too closely as sperm whales can take milk from any milk-producing female in its social group.(1)The underlined word “they” in paragraph 2 probably refers to _____.A.the whalesB.the diversC.the photosD.the mothers(2)According to Justin Hart, the young sperm whale ____.A.found its family with his helpB.suffered a lot in the cold watersC.lost contact with its family for daysD.slammed as a means of communication(3)What do we know about sperm whales?A.The young are independent.B.They are highly social animals.C.They tend to live in warm sea waters.D.Females take turns to care for babies.(4)What would be the best title for the text?A.Baby whales perform slamming with joyB.Sperm whales -- fairly intelligent animalsC.Lost sperm whale baby reunited with its familyD.Slamming-- a way of communication among whales
数学 试题推荐