题目

如图所示为一简单欧姆表原理示意图，其中电流表G的满偏电流Ig=300μA，内阻Rg=100Ω，可变电阻R的最大阻值为10kΩ，电池的电动势E=1.5V，内阻r=0.5Ω，图中与接线柱A相连的表笔颜色应是_____色。按正确使用方法测量电阻Rx的阻值时，指针指在刻度盘的正中央，则Rx=______kΩ。  答案：红    5解析:略 Step into an American preschool classroom today and you are likely to fall into a so-called print-rich environment，every surface colorfully decorated with instructional posters，classroom rules，chedules，and mottos，few of which a 4-year-old can understand in fact． Besides the confusing things on classroom walls，teaching methods and curriculums have changed recently，by which more time is spent on what’s called “seat work”一workbooks and worksheets—but less time devoted to music and art．School—readiness skills are essential for the youngest learners to move on to a subsequent stage. As a result, expectations that may arguably have been reasonable for 5-and 6-year-olds, such as bemg able to sit at a desk and using pencil and paper，are now directed at even younger children, who lack the motor skills and attention span to be successful． However，parents of preschoolers tend to be on board with these changes，because they fear that the old—fashioned pleasures of unhurried learning have no place in today’s highly competitive world．The stress is obvious：Pick the “wrong” preschool and your child might not go to college．She might not be employable. She might not even be allowed to start first grade! As preschoolers are learning so much academic knowledge at earlier ages，they seem somehow less curious and less engaged．Some teachers say that more children today seem to lack the language skills．The real focus in the preschool years should not be just on vocabularv and reading，but on talking and listening．By talking with adults, and one another，they pick up information，learn how things work and solve puzzles that trouble them．For our littlest learners，what could be more important than that?1.Which of the statements does the author probably agree with?A．Younger children can fully understand the instructional things in classrooms．B．3-and 4-year-olds shouldn’t be expected too much in school readiness skills．C．More time should be spent on“seat work’’ instead of music and art．D．Even 5-and 6-year-olds have good motor skills and attention span．2.The underlined phrase “be on board with” in the third paragraph most probably means “ ”.A．accept B．reject C．doubt D．worry3.Why are parents so picky when choosing a preschool for their kids?A．Because some preschools are too old fashioned．B．Because a wrong preschool might ruin kids’ future．C．Because the competitions between kindergartens are fierce．D．Because it is easy for them to choose a right preschool．4.What’s the best title of the passage?A．New Preschool Breaking down the Kids．B．The Early Bird Gets the Worm．C．Preschool，the Gatekeeper to Elementary School?D．Seat work，a Better Choice for the Youngest Kids?