题目

如图所示，质量为的闭合铝框，用较长细线悬挂起来，静止铝框的中央距地面，今有一质量的磁铁以水平速度射入并穿过铝框，落在距铝框原位置水平距离处，在磁铁穿过铝框后，求： （1）铝框向哪边偏转？能上升多高？ （2）在磁铁穿过铝框的整个过程中，框中产生了多少电能？ 答案：（1）向右偏，0.2米；（2）1.88焦耳 阅读理解 　　Forty-two of the fifty American states offered some kind of public online learning this past school year．One state, Michigan, now requires all students to have an online learning experience before they finish high school．Even the idea of a school has changed since the rise of the Internet in the 1990s． 　　A new report from the Center for Evaluation and Education Policy at Indiana University says eighteen states have full-time virtual schools．There are no buildings．All classes are online． 　　Florida started the first statewide public virtual school in the United States in 1997．Today, the Florida Virtual School offers more man ninety courses．56,000 students were enrolled as of December．Almost sixty percent were female．The school's website says each student was enrolled 　　in an average of two classes． 　　Florida Virtual School has now opened the Florida Virtual Global School．Students in other countries pay for classes．Janet Heiking teaches an English class．She lives in Indianapolis, Indiana．Her students live as far away as Africa and Japan．She says they are taking her Advanced Placement class to prepare for attending an American college．They can earn college credits by passing the AP test． 　　So how good are virtual schools? Studies have shown mixed results, as a new report from Indiana University notes．For example, students at Florida Virtual School earned higher grades than those taking the same courses the traditional way．And they scored higher on a statewide test．But virtual school students in Kansas and Colorado had lower test scores or performed at a lower level than traditional learners．Studies also find that virtual schools may not save much in operating costs． 　　Education experts say the mixed results suggest the need for more research to find the best ways to teach in virtual schools．A1so, they say schools of education need to train more teachers to work in both real and virtual classrooms． (1) A virtual school is one that ________． [　　] A． is set up after the rise of the Internet B． uses textbooks as a main teaching resource C． uses computer-based resources and has no teachers D． has online classes and no real classrooms (2) The first statewide public virtual school in the USA was started in ________． [　　] A． Florida B． Indiana C． Michigan D． Colorado (3) Florida Virtual School is open to ________． [　　] A． students in Indiana B． students only around the USA C． students across the world D． only foreign students (4) Foreign students take Advanced Placement classes for the eventual purpose of ________． [　　] A． earning college credits B． entering an American college C． learning advanced science D． passing the AP test (5) From the passage we learn that ________． [　　] A． the majority of virtual school students in Florida are male B． all senior students m Michigan have an online learning experience C． virtual schools are better than traditional schools D． both real and virtual classrooms need more trained teachers