【真题试题】（2007年单项选择第23题）A．保证具有从属性 B．保证具有相对独立性

若金属单质的活泼性越强，则对应的阴离子越难被还原。现有Cu（NO₃）₂、Mg（NO₃）₂和AgNO₃组成的混合液向其中加入适量锌粉，首先置换出的是(    )

A．Mg

B．Cu

C．Ag

D．H₂

某同学在“研究平抛物体的运动” 的实验中，在已经判定平抛运动在竖直方向为自由落体运动后，再来研究水平方向的运动。他先调整斜槽轨道槽口末端水平，然后在方格纸上建立好直角坐标系xOy，将方格纸上的坐标原点O与轨道槽口末端重合，Oy轴与重垂线重合，Ox轴水平。实验中使小球每次都从斜槽同一高度由静止滚下，经过一段水平轨道后抛出。依次均匀下移水平挡板的位置，分别得到小球在挡板上的落点，并在方格纸上标出相应的点迹，再用平滑曲线将方格纸上的点迹连成小球的运动轨迹如图乙所示。已知方格边长为L，重力加速度为g。

（1）小球平抛的初速度v₀＝        ；

（2）小球竖直下落距离y与水平运动距离x的关系式为y＝           。

FS常有家族史，若干大家系连锁分析提示___________________的可能性，病理基因在___________________和___________________。

交流耐压试验时，应测量试验电压的峰值Um，并使Um/√2＝标准规定的试验电压U（有效值）。

How many of us would temp for three years while we waited for the perfect job Not many of us, perhaps. But Wentworth Miller, the "Prison Break" star, said he chose to wait even longer time (1) he found the right job.
"Actually I think it might have been three or four years until I was lucky enough to get guest (2) on TV shows," said Miller, 34, who rose to international stardom (3) to "Prison Break" in 2006. That kind of patience and p will was portrayed in "Prison Break". Miller (4) engineering wizard Michael Scofield, who tries everything to break out of a Chicago (5) with his brother. Miller said he was fond of his character, (6) he said "exists in shades of grey".
Miller comes from a (7) of teachers. He said he didn’t seem fated for a career in the arts, (8) his passion for acting. After (9) from Princeton with an English degree, he moved (10) his parents’ request to Los Angeles to look for a stable life. He started (11) in a little company that made television movies. This (12) simply faxing, filing, walking the boss’ dog and going to the store for the boss’ lunch. Every weekend during the summer, Miller (13) go to the office (14) he didn’t have air-conditioning. "I would hang (15) in the conference room and set up camp and rob the company kitchen," recalled Miller.
(16) , Miller realized he still had questions about his choice. He decided to quit. But the boss said he was making a mistake and offered him a well-paid assistant position. "I eventually (17) that if I did the corporate job, it would be great if I was successful, but I would always wonder about the (18) . If I did the acting and was successful, I would never wonder (19) that job," he explained. He quit and temped (20) many people in the entertainment industry.
Now, he’s a hot star and has people coming up to him at film festivals saying, "Weren’t you the one who (21) to stand by the copy machine "
"That was tough, but I’m glad I have that perspective. Because now I’m at a point (22) big shots laugh at all my jokes and I think, You know, I got coffee for people like you for six years’. So I know what’s (23) , because I’ve seen the other side." But what if, when he was offered the corporate job, there had been more money "It was never about the (24) There’s a kind of excitement that comes along with acting. I can’t find it anywhere else. Even if I had to go back to temping, even if this is not the beginning of an amazing career, I would not (25) making that jum
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