机械零件成形方

某颗人造地球卫星在距地面高度为h的圆形轨道上绕地球飞行，其运动可视为匀速圆周运动。已知地球半径为R，地面附近的重力加速度为g。

请推导：(1)卫星在圆形轨道上运行速度  (2)运行周期的表达式。

（1）当线圈的ab边刚进入磁场时，它可能做什么运动，并分析各种运动下h的条件．

（2）设ab边刚进入磁场和刚穿出磁场时都作减速运动，且加速度大小相等。求线框经过磁场的过程中产生的焦耳热。

（3）设线圈刚好以匀速运动进入匀强磁场，此时线圈中的电流为I₀，且线圈的边长L=h磁场的宽度H=2h。请在坐标系中定性画出线圈进入磁场到离开磁场的过程中，线圈中的电流i随下落高度x变化的图象。（不需要计算过程，按图象评分，设电流沿abcda如方向为正方向，x以磁场上边界为起点。）

经常居住于英国的法国籍夫妇甲和乙，想来华共同收养某儿童。对此，下列哪一说法是正确的?

A.甲、乙必须共同来华办理收养手续 

B.甲、乙应与送养人订立书面收养协议 

C.收养的条件应重叠适用中国法和法国法 

D.若发生收养效力纠纷，应适用中国法

The doctor-patient relationship is one of the (1) relationships in life, but many people say this relationship is beyond (2) . Can this relationship be saved The answer is (3) yes, because it must. And if that is lost, medicine becomes a technology and is (4) . In part the crisis in medicine began with doctors (5) themselves from patients.
The more critical work of a doctor happens in the taking of the human (6) . (7) is the most important and most difficult single transaction. The studies show that (8) of all the valuable information that leads to correct diagnosis comes from the history. Another (9) comes from the physical examination, 10% comes from simple (10) tests, and 5% comes from all the complex (11) . So listening is vital, because listening is not merely listening, but to establish a (12) .
But some doctors think listening is (13) . They like to use complex and costly (14) , and use (15) that create adverse reactions and require (16) . They don’t like to listen. Because there’s no premium on listening and that there’s no (17) for listening.
Even so, the doctor-patient relationship is not (18) saving. Because people may ask, what is good health And good health begins first and foremost with (19) . If you don’t care for a (20) , be somebody else, but don’t be a doctor!

企业在安全生产许可证有效期内，未发生死亡事故的，安全生产许可证届满时，经原安全生产许可证颁发管理机关同意，（）。

A.不再审査，有效期延期3年

B.必须再次审查，有效期増加2年

C.不再审查，有效期直至发生死亡事故

D.必须再次审查，重新办理