问题
单项选择题 A1型题
生活饮用水卫生标准中，规定细菌总数的含量是（）
A.＞3个／ml
B.100个／ml
C.＞3个／L
D.＞100个／L
E.＞3000个／L
答案
参考答案：B
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生活饮用水卫生标准中，规定细菌总数的含量是（）
A.＞3个／ml
B.100个／ml
C.＞3个／L
D.＞100个／L
E.＞3000个／L
参考答案：B
在测3.8V小灯泡（电阻大约为10Ω左右）额定功率的实验时，小明连接了如图甲所示的电路，其中电源电压为6V。
（1）在连接电路时，开关必须 ，请将实物电路连接完整（要求：滑动变阻器的滑片向左移动时小灯变亮）。
（2）若在连接电路时，有A(5Ω 1A)、B(10Ω 0.5A)和C（15Ω 0.2A）三个滑动变阻器可供选择，则应该选择变阻器 （A/B/C）连入电路，才能保证实验顺利进行。
（3）小明合理地连接好电路，闭合开关，发现无论怎样调节滑动变阻器灯泡都不亮，小明分析后确定是灯泡的故障。若电流表没有示数，电压表有示数，可以判断灯泡 ；若电流表有示数，电压表没有示数，可以判断灯泡 。
（4）下表为某小组的实验记录：
| 实验序号 | 电压表示数/V | 电流表示数/A | 功率/W | 额定功率/W |
| 1 | 3.0 | 0.36 | 1.08 |  |
| 2 | 3.8 | 0.40 | 1.52 | |
| 3 | 4.5 | 0.42 | 1.89 |
（5）在科学探究过程中，经常需要多次实验．如在本实验中，综合分析实验数据，你能发现
，可见这里的多次实验是为了发现不同现象背后的共同规律；有的多次实验是为了求平均值以减小实验误差，如： （填实验名称）。
（6）在某次实验时，电压表出现了故障不能使用，小明向老师借了一只定值电阻R0（R0值已知），设计了如图乙所示的电路，继续测量额定电压为U额的小灯泡的额定功率：测量时，应闭合开关S和 ，调节滑动变阻器，当电流表的示数为 时，小灯泡正常工作；
断开所有开关后，再将开关S和 闭合，读出电流表的示数为I；
算出小灯泡的额定功率P额= (用I、U额 和R0表示)。
One of my fondest memories as a child is going by the river and sitting idly on the bank．There I would 36 the peace and quiet, watch the water rush 37 and listen to the singing of birds and the rustling of 38 in the trees．I would also watch the bamboo trees 39 under pressure from the wind and watch them 40 gracefully to their original position after the wind had 41 ． When I think about the bamboo tree's ability to bounce back to its original position, the word "resilience" comes to mind．When used in 42 to a person, this word means the ability to readily 43 from shock, depression or any other situation that stretches the limits of a person's 44 ． Have you ever felt like you are at your 45 point? Thankfully, you have survived the experience to live to talk about it． During the 46 you probably felt a mix of emotions that threatened your health．You felt emotionally drained（枯竭）, 47 exhausted and you most likely stood 48 physical symptoms． Life is a 49 of good times and bad times, happy moments and unhappy moments．The next time you are experiencing one of those bad times or unhappy 50 that take you close to your breaking point, bend, 51 don't break．Try your best not to let the situation get the best of you． A measure of hope will take you 52 the unpleasant ordeal （考验）．With 53 for a better tomorrow or a better situation, things may not be as bad as they seem to be．The unpleasant ordeal may be easier to 54 if the final result is worth having． If life gets 55 and you are at your breaking point, show resilience．Like the bamboo tree, bend, but don't break!
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