Diseases spread by insects are encouraged when climatic conditions are favorite to the propagation of the vectors . 当气候条件适于媒介昆虫繁殖时，由昆虫传播的疾病即行蔓延。
2.
Many dangerous diseases are carried by insects 许多危险的疾病是由昆虫传播的。
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Many serious diseases are carried by insects 很多严重的疾病都是由昆虫传播的。
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Many serious diseases are carried by insects 许多严重的疾病都是昆虫传播的。
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It has long been established that many human serious diseases are carried by insects 早就证明人类的许多严重疾病都是昆虫传播的。
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The sudden emergence of an insect - borne disease of livestock in northern europe has plunged the agricultural sectors of three countries into crisis 在欧洲北部突然出现的一种由昆虫传播的牲畜疾病使得三个国家的农业部门陷入了危机之中。
