题目

如图所示，带有正电荷的A粒子和B粒子同时从匀强磁场的边界上的P点分别以30°和60°（与边界的交角）射入磁场，又同时从磁场边界上的Q点飞出.设边界上方的磁场范围足够大.下列说法中正确的是 A.若A粒子是α粒子，则B粒子可能是质子B.若A粒子是α粒子，则B粒子可能是氘核C.A粒子和B粒子的速度之比为D.A粒子和B粒子的速度之比为A rich man was camping alone on a hill. One day it began to rain and the rain made the tent wet. At last he 1 make his way home. As he passed a beautiful house he 2 to look for rest. A lady in 3 walked past him with her 4 holding up high. Following her were her two pretty daughters. They stopped and stared at him  5  .“Who are you? We don’t like tramps（流浪汉）going around 6 our home .”one of them shouted.“Go away at once. ”cried the other.“But I’m not a  7 . ”said the man, “All I want is food and stay for the night.”“How 8 you come here? Go away at once!” they 9 “We don’t like your feet around our house. Go, go!”The man moved on and reached a  10 house. On entering it he saw a 11   preparing their supper. Though the light was 12 and the furniture was poor, it made him feel 13  and comfortable.“Can I have some 14   and rest for the night?” he asked. “Of course, friend,” said the woman, bringing forward a little chair for him. “We are going to15 our supper. Come and 16 us.”The food was not  17 but they shared it with the stranger. That night they let him sleep on theirbed  18  they themselves used the stable（厩）. Early the next morning, the man said good-bye to them. Their   19  left him a memory full of thanks. When he reached home he   20  ordered a lovely house to be built for the couple in the woods.【小题1】A．had to B．must C．shouldD．would【小题2】A．triedB．managedC．askedD．stopped【小题3】A．sightB．clothC．silkD．trouble【小题4】A．noseB．headC．eyesD．hands【小题5】A．curiously B．suddenlyC．surprisinglyD．angrily【小题6】A．aroundB．overC．toD．at【小题7】A．madamB．trampC．thiefD．stranger【小题8】A．doB．canC．willD．dare【小题9】A．explainedB．continuedC．repeatedD．announced【小题10】A．bigB．smallC．lovelyD．dirty【小题11】A．womanB．manC．personD．couple【小题12】A．weakB．brightC．darkD．strong【小题13】A．sadB．coldC．warmD．clean【小题14】A．clothB．foodC．lightD．chair【小题15】A．prepareB．cookC．buyD．have【小题16】A．joinB．helpC．attendD．enjoy【小题17】A．enoughB．scaryC．shortD．lot【小题18】A．andB．whileC．thenD．when【小题19】A．coldnessB．sicknessC．kindnessD．thank【小题20】A．quicklyB．finallyC．happilyD．quietly