题干

下列说法中不正确的是()

A:目前已经建成的核电站的能量来自于重核裂变

B:自由核子组成原子核时,其质量亏损所对应的能量大于该原子核的结合能

C:卢瑟福依据极少数α粒子发生大角度散射提出了原子核式结构模型

D:氢原子核外电子从半径较小的轨道跃迁到半径较大的轨道时,电子的动能减小,原子总能量增加

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B

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    Camels are large animals living in dry areas. There are two species of camels; the Arabian camel with a single hump(驼背) from the dry desert areas of West Asia, and the Bactrian camel with two humps from Central and East Asia. Camels are over 7 feet tall and weigh over 1,600 pounds. They will live up to 40 to 50 years. Most camels are domesticated(驯化) and fed by people. Camels are plant-eaters.

    Camels are very strong animals with wide, padded feet. They have thick leathery pads on their knees and chest. Camels have nostrils(鼻孔)that can open and close, protecting them from the desert environment. Bushy eyebrows and two rows of long eyelashes protect their eyes from sand. Their mouth is extremely tough, allowing camels to eat thorny(带刺的)desert plants. Their widened feet help them move without sinking into the sand. Their thick coats reflect sunlight, and also protect them from the intense heat from desert sand. Their long legs help by keeping them further from the hot ground.

    Camels can go without food and water for 3 to 4 days. They do not store water in their humps as is commonly believed.The humps are actually a container of fat. Camels are incredibly well-adapted to their environment. When conditions heat up, camels can increase their own body temperature, which prevents sweating and therefore water loss. They may not sweat at all during the day.

    Camels are sometimes called“ships of the desert”because people ride them around the hot, dry deserts of the world.However, the number of camels is becoming smaller for various reasons.