单选题“一把钥匙开一把锁”属于教学中的______原则。

单选题下列书写不正确的一组是( )。A．真知灼见 深居简出 一劳永逸B．买椟还珠 初生牛犊 连篇累牍C．先发制人 投机倒把 金榜提名D．言简意赅 戴罪立功 人才辈出

单选题中枢神经系统的最高部位是______。

单选题下图表示果酒和果醋制作过程中的物质变化过程，下列叙述正确的是()。A．过程①和②都只能发生在缺氧条件下B．过程①和③都发生在酵母细胞的线粒体中C．过程③和④都需要氧气的参与D．过程①—④所需的最适温度基本相同

单选题教育科学体系中的基础学科是( )。

单选题Disposing of waste has been a problem since humans started producing it. As more and more people choose to live close together in cities, the waste disposal problem becomes increasingly difficult. During the eighteenth century, it was usual for several neighboring towns to get together to select a faraway spot as a dump site. Residents or trash haulers (垃圾托运者) would transport household rubbish, rotted wood, and old possessions to the site. Periodically some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by. Factories, mills, and other industrial sites also had waste to be disposed of. Those located on rivers often just dumped the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem. Several facts make these choices unacceptable to modern society. The first problem is space. Dumps, which are now called landfills, are most needed in heavily populated areas. Such areas rarely have empty land suitable for this purpose. Property is either too expensive or too close to residential neighborhoods. Long distance trash hauling has been a common practice, but once farm areas are refusing to accept rubbish from elsewhere, cheap land within trucking distance, of major city areas is non-existent. Awareness of pollution dangers has resulted in more strict rules of waste disposal. Pollution of rivers, ground water, land and air is a price people cannot longer pay to get rid of waste. The amount of waste, however, continues to grow. Recycling efforts have become commonplace, and many towns require their people to take part. Even the most efficient recycling programs, however, can hope to deal with only about 50 percent of a city"s reusable waste. 根据短文内容，选择正确的答案。

单选题教学评价的依据是______。

单选题东汉画像石______

单选题教师在课堂上采用小组讨论的教学方法，重点是培养学生的______

单选题根据中心地理论，各级中心地的服务范围均表现为( )。

单选题设a，b∈R，i是虚数单位，则“ab=0”是“复数为纯虚数”的______．

单选题有目的地创设生动具体的场景，引发学生的态度体验，激发学生的好奇心，这一教学策略属于______

单选题教育守法首先要求守法的主体应当遵守______。 A.《中华人民共和国义务教育法》 B.《中华人民共和国教育法》 C.《中华人民共和国教师法》 D.《中华人民共和国宪法》

单选题下列句子不是复句的一项是（）。

单选题The Earth"s axis (轴) is an imaginary line that runs through the middle of the Earth from the North Pole to the South Pole. The axis of the earth is tilted (倾斜)about 23.5 degrees. This tilt of the earth results in our seasons. In June, the Northern Hemisphere (半球)is tilted toward the sun, so the people in the Northern Hemisphere have longer and warmer days. The days are shorter and colder in the Southern Hemi-sphere in June, because the Earth is tilted away from the sun. The days start getting shorter in the Northern Hemisphere and longer in the Southern Hemisphere after about June 21. This is the first day of summer in the Northern Hemisphere and the first day of winter in the southern hemisphere. Daytime lasts exactly as long as nighttime on the first day of autumn ( about September 21 ) and the first day of spring (about March 21 ). The first day of winter in the Northern Hemisphere, usually December 21, is the shortest day of the year in the Northern Hemisphere and the longest day of the year in the Southern Hemisphere. The days are longer in summer and shorter in winter the further you move from the equator. It"s generally dark on a summer night in Florida by 8.30 p.m., but in Vermont, there will still be some light at 10:00 p.m. The situation is reversed(相反的)in winter, where the sun will go down in Vermont by 3:45 p.m. while there remains light in Florida until 5:15 p.m. Northern Alaska is called the "Land of the Midnight Sun", because it never gets dark during the summer months. That part of the Earth is facing the sun all day and all night. Antarctica never sees daylight during those months. The situation is reversed in December and January when northern Alaska never sees the sun while it continues to light the sky at night in Antarctica.

单选题已知全集U=1，2，3，4，5，6，7，8，M=1，3，5，7，N=5，6，7，则=______．A．5，7B．2，4C．2，4，8D．1，3，5，6，7

单选题保持信息在1秒钟以内的记忆是______。 A．短时记忆 B．长时记忆 C．瞬时记忆 D．永久记忆

单选题下列离子方程式书写正确的是()。A．向明矾溶液中加入过量的氢氧化钡溶液：B．向氢氧化亚铁中加入足量的稀硝酸：C．向磷酸二氢铵溶液中加入足量的氢氧化钠溶液：D．向CH2BrCOOH中加入足量的氢氧化钠溶液并加热：

单选题体现“可”“可以”等要求的教育法律规范是______。

单选题在学习风格的五个组成成分中，对学习影响最深入的是______。