在农业生产上，利用昆虫的性外激素所不能达到的目的一项是： （   ）            

政治民主化是近代历史发展的趋势，且西方各国民主政治呈现出不同面貌。阅读下列材料：

材料一 英国的内阁制被称为“责任内阁制”，所谓责任内阁制是指内阁由议会产生并对议会负责的一种行政权力的组织形式。……内阁的主要职权是协调和指导政府各部门的活动，从而制定出一种始终一贯的政策。有的政治学家称它为把行政与立法两部门连接起来的一个“纽扣”，又称它为议会推选出来的统治全国的委员会，更严格地说，它是下院多数党的一个委员会，少数党是没有代表在内的，这是它与其他的议会委员会不同的地方。……英国内阁的建立是没有任何正式的成文的法律作为依据的，它是在漫长的历史发展过程中，依据惯例逐步形成的。

——马啸原《西方政治制度史》

材料二 在费城所起草的宪法是实验时期最伟大的创造性胜利……战后人们最初反对君主制和贵族政治的思想，引导着美国人建立了一些行政首脑软弱无力、上院不起什么作用的州政府；新的宪法则建议有一个权力很大的行政首脑和同众议院权力相当的参议院。“邦联条例”建立了由各州政府控制的、而和公民个人没有直接联系的全国政府；新宪法则建议成立一个独立于各州政府之外的全国政府，它有一个直接由合众国人民选举的众议院和一些直接对人民行使司法权的联邦法院。“邦联条例”把全国政府置于一个由代表组成的一院制国会的手中，只赋予它很小的权力；新宪法则把全国政府分成几部分以防止滥用职权，并赋予它真正的权力。

——J·布卢姆等《美国的历程》

材料三 德意志帝国没有内阁，只有一个首相，国家各个部门的负责人实际上都是由他任命的，所有的官员都只对首相负责，而首相则对皇帝负责。德国自由党成立时，曾要求成立一个“帝国责任内阁”，1884年4月5日联邦议会按照俾斯麦的意见通过决议反对这项要求，决议说：“在德意志帝国境内成立责任内阁制只能削弱各联邦成员目前在联邦议会行使的、由条约给以其保障的权力。”

——马啸原《西方政治制度史》

请回答：

    Lost cities that have been found

    The White City

    In 2015, a team of explorers to Honduras in search of “the Lost City of the Monkey God” led to the discovery of the White City. They found the ruins in the Mosquitia region of the Central American country — which is known for poisonous snakes, vicious jaguars and deadly insects. It is believed that local people hid here when the Spanish conquerors(征服者)occupied their homeland in the 16th century.

    Canopus and Heracleion

    Modern researchers were teased by the ancient writings about the Egyptian cities Canopus and Heracleion — where Queen Cleopatra often visited. But the cities weren't found until 1992, when a search in Alexandria waters found that the two cities had been flooded for centuries. Artifacts(史前器物)showed that the cities once highly developed as a trade network, which helped researchers piece together more about the last queen of Egypt.

Machu Picchu

    A Yale professor discovered “the Lost City in the Clouds” in 1911. A combination palaces, plazas, temples and homes, Machu Picchu displays the Inca Empire at the height of its rule. The city, which was abandoned in the 16th century for unknown reasons, was hidden by the local people from the Spanish conquerors for centuries, keeping it so well preserved.

Troy

    The ancient city of Troy in Homer's The Iliad was considered a fictional setting for his characters to run wild. But in 1871, explorations in northwestern Turkey exposed nine ancient cities layered(层叠)on top of each other, the earliest dating back to about 5,000 years before. It was later determined that the sixth or seventh layer contained the lost city of Troy and that it was actually destroyed by an earthquake, not a wooden horse.