【单选题】The first president in the U.S. history who resigned because of a scandal is______.
【单选题】Franklin Delano Roosevelt was the U.S. President when many businesses were ______ during the Great Depression.
【简答题】石英晶体振荡器是利用石英晶体的()工作的,其频率稳定度很高,通常可分为串联型晶体振荡器和并联型晶体振荡器两种。
【判断题】学习是个体在任何情境下,由于练习或反复经验而产生的行为或行为潜能的比较持久的变化。
【单选题】The _______ of the U.S. is now . [ ]
【单选题】According to a major U.S. newspaper, President Bush will ______ a mission to the country W investigate the cause of the sudden disappearance of the two diplomats.