某种果蝇是家禽的致命性寄生生物，在一实验室里，用杀虫剂和电离辐射分别处理这种果蝇的两个数量相同的群体，电离辐射能导致雄果蝇不育，实验结果如图：

如图所示，固定的竖直光滑U型金属导轨，间距为L，上端接有阻值为R的电阻，处在方向水平且垂直于导轨平面、磁感应强度为B的匀强磁场中，质量为m、电阻为r的导体棒与劲度系数为k的固定轻弹簧相连放在导轨上，导轨的电阻忽略不计．初始时刻，弹簧处于伸长状态，其伸长量为x₁= $\frac{mg}{k}$ ，此时导体棒具有竖直向上的初速度v₀．在沿导轨往复运动的过程中，导体棒始终与导轨垂直并保持良好接触．则下列说法正确的是（   ）

1. What was his ____ (反应) to your answer?

2. We have bought lots of ____ (设备) for our new lab.

3. The lock has ____ (生锈) and needs oil.

4. I came to the ____ (结论) that he had been lying.

5. He kept his ____ (平衡) with his arms on top of the wall.

6. The ____(沸腾的) kettle was giving off steam.

7. As a result of pollution，there are many dead fish ____ (漂浮) on the water.