下列有关介水传染病的流行特点，不正确的说法是( )。
A．如果水源一次大量污染后，可导致暴发流行
B．流行具有明显的地区性
C．绝大多数患者有饮用同一水源的历史
D．发病具有明显的季节性，多在夏秋季流行
E．一旦对污染源采取措施，流行既能迅速得到控制
参考答案：D
解析： 介水传染病流行特征是：①短时间内出现大量病人，症状相同，暴发流行，甚至可导致成千上万人发病；②病人曾饮同一水源，发病集中在被污染水源区域；③消除了污染源及加强了饮用水消毒等卫生防护措施后，疾病便能得到控制。
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| It was getting dark. Some children and two Canadian women were still 1 on the ice near a big hotel. They were having a good time. Suddenly the ice 2 , and one of the boys fell into the water. The children shouted "Help, Help" They didn't know 3 to do. The two Canadian women heard 4 and skated over to get the boy out of the water. The ice was 5 , the two Canadians fell into the water, too. But they tried their best to 6 the little boy. They knew they must be 7 . If they didn't push him up onto the ice, he would soon die. Many people ran over to 8 . Some of them had ropes and poles. A young man jumped into the water to save the 9 people. The boy and the two Canadians women were out of water at last. One of the women didn't feel well. She was sent to the 10 at once. But she felt very happy because the boy was safe. | ||||
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