题目

如图，小贤为了体验四边形的不稳定性，将四根木条用钉子钉成一个矩形框架ABCD，B与D两点之间用一根橡皮筋拉直固定，然后向右扭动框架，观察所得四边形的变化．下面判断错误的是(    )A．四边形ABCD由矩形变为平行四边形            B．BD的长度增大                        C．四边形ABCD的面积不变                      D．四边形ABCD的周长不变Heaviest snow in half a century hit the south of the country. It snowed continuously for half a month, _______the railways, highways, and runways in the airfields. Ice wrapped and paralyzed（使瘫痪）the power and communication system. Many people were_______in railway stations, bus stations and airports, and_______in cars, buses and trains. Governments and people did everything they could to fight the snow_______, resulting in the good news that no one was killed from_______and hunger. Gradually, trapped people all went back home_______. While fighting the snow, people forgot their_______until a moving story of a swallow couple was widely_______on the Internet.Being hungry and cold, the swallow couple tried to fly_______people's home to warm themselves, but every house was closed________. They jumped and flapped their wings to________the attention of the people inside the house, but failed. The wife’s body was________, she could not move any longer. The husband came near and wrapped his wife with his wings. He lost his________soon because of his opened wings. The couple died in the end.The next morning, the housemaster went to the balcony to________his flowers because of concern and saw a________swallow outside the window pane. Touching it, he found that they were two________together. Moved to tears, he took them in, giving them some________, but in vain. He found a small cardboard box, laid them in and________them in the back garden.In my hometown, in the countryside, a swallow family lives in the________of my house. I wonder if they will come back this spring________they did.1.A. protecting B. maintaining C. blocking D. keeping2.A. restricted B. stuck C. surrounded D. persuaded3.A. even B. still C. yet D. nevertheless4.A. disturbance B. occurrence C. incident D. disaster5.A. cold B. disease C. poverty D. thirsty6.A. merrily B. safely C. excitedly D. exhaustedly7.A. family B. distant relatives C. parents D. animal friends8.A. broadcast B. written C. spread D. identified9.A. into B. through C. beyond D. across10.A. tightly B. early C. secretly D. quickly11.A. pay B. attract C. resist D. keep12.A. injured B. lifted C. frozen D. broken13.A. heat B. strength C. direction D. eyesight14.A. water B. plant C. dig D. check15.A. dead B. drunk C. lively D. lovely16.A. touching B. embracing C. living D. lying17.A. warmth B. food C. kindness D. fruit18.A. left B. sheltered C. buried D. threw19.A. roof B. basement C. window D. wall20.A. when B. as C. unless D. if