如下图甲所示，在一根横跨河流两岸的硬塑料管内穿有三根完全相同的导线。为了辨别哪两个线头为同一根导线的两端，工人师傅用图乙所示的“测通器”来进行测试。他首先将A和B连接起来，然后将“测通器”的m连接在D上，将n连接在F上，发现此时小灯泡发光……。工人师傅据此可以做出什么判断?下一步他将如何操作才能最终搞清每根导线的两端?

图中弯曲的撑竿表明力能使物体发生 ____；运动员推开撑竿后不会立即落下，由于 ____将继续向前，从而越过横杆．

2015年8月19日国务院总理***主持召开国务院常务会议，会议决定从2015年10月1日起到2017年底，依法将减半征收企业所得税的小微企业范围，由年应纳税所得额20万元以内(含20万元)扩大到30万元以内(含30万元)。此次税收政策调整，其合理的传导顺序是（  ）

①投资需求释放 ②更多小微企业享受税收优惠 ③缓解经济下行压力 ④自主创业积极性提高

DDT是一种不易分解、化学性质十分稳定的有机杀虫剂．某海洋生态系统中甲、乙、丙、丁4种生物之间存在食物关系，经检测这4种生物及海水中DDT含量的情况如下表，那么最可能的食物链构成是（  ）

    When Mr. David retired(退休), he bought a small house in a village near the sea. He liked it and hoped to live a quiet life in it. But to his surprise, many visitors came to see his house in summer holidays, for it was the most interesting building in the village. From morning to night, there were visitors outside the house. They kept looking into the rooms through the windows and many of them even went into the house. He decided to drive the visitors away. So he put a notice on the window. The notice said，“If you want to satisfy your curiosity(好奇心), come in and look around. Price: twenty dollars.”Mr. David was sure that the visitors would stop coming, but he was wrong. More and more visitors came and Mr. David had to spend every day showing them around his house. “I came here to retire, not to work as a guide(导游)”, he said angrily. In the end, he sold the house and moved away.