电弧的主要影响：延长了电路的（）电弧高温烧坏开关的触头。

Last night I was driving from Harrisburg to Lewisburg，distance of about eighty miles. It was late. Several times I got stuck behind a slow-moving truck on a narrow road with a solid white line on my left, and I became increasingly impatient.

At one point along an open road, I came to a crossing with a traffic light. I was alone on the road by now, but as I drove near the light, it turned red and I made a stop. I looked left, right and behind me. Nothing. Not a car, no suggestion of car lamps, but there I sat, waiting for the light to change, the only human being for at least a mile in any direction.

I started wondering why I refused to run the light I was not afraid of being caught, because there was clearly no policeman around, and there certainly would have been no danger in going through it.

Much later that night, the question of why I'd stopped for that light came back to me. I think I

stopped because it's part of a contract(契约)we all have with each other. It's not only the law, but it is an agreement we have, and we trust each other to honor it: we don't go through red lights.

Trust is our first inclination(倾向).Doubting others does not seem to be natural to us. The whole construction of our society depends on mutual(相互)trust, not distrust. We do what we say we'll do; we show up when we say we'll show up; and we pay when we say we'll pay. We trust each other in these matters, and we're angry or disappointed with the person or organization that breaks the trust we have in them.

I was so proud of myself for stopping for the red light that night.

小题1:Why did the author get impatient while driving?

A．He was lonely on the road.

B．He was slowed down by a truck.

C．He got tired of driving too long.

D．He came across too many traffic lights.小题2:What was the author's immediate action when the traffic light turned red?

A．Stopping still.

B．Driving through it.

C．Looking around for other cars.

D．Checking out for traffic police.小题3:The event made the author strongly believe that __________.       

A．traffic rules may be unnecessary

B．doubting others is human nature

C．patience is important to drivers

D．a society needs mutual trust小题4:Why was the author proud of himself?

A．He kept his promise.

B．He held back his anger.

C．He followed his inclination.

D．He made a right decision.

（2013河南）酸、碱、盐是几类重要的化合物，他们之间能发生复分解反应。

（1）复分解反应发生的条件是有沉淀析出，或有气体放出，或有              生成。

（2）某化学小组进行“酸和碱的中和反应”实验：将盐酸滴入一定量的澄清石灰水中，实验无明显现象。取反应后的部分溶液加热、蒸干、得到白色固体。

以下是探究白色固体成分的实验，已知CaCl₂溶液呈中性。请填写下表：

实验操作	测定结果	白色固体成分
用pH试纸测定反应后溶液的酸碱度，操作方法是	pH＞7
		CaCl2

实验反思：无明显现象的中和反应可借助酸碱指示剂判断反应终点。

（3）“粗盐提纯”指除去NaCl中的泥沙和MgCl₂、CaCl₂、Na₂SO₄等杂质。

某同学设计了除去三种可溶性杂质的实验方案：先将固体溶解，然后向其中依次加入过量的BaCl₂、NaOH、Na₂CO₃溶液，充分反应后过滤，蒸发结晶。请回答：

部分物质的溶解性表（室温）
	OH－	Cl－	SO	CO
H＋		溶、挥	溶	溶、挥
Ba2＋	溶	溶	不溶	不溶
Ca2＋	微溶	溶	微溶	不溶
Mg2＋	不溶	溶	溶	微溶

①溶解、过滤和蒸发操作中都用到一种玻璃仪器，该仪器在蒸发操作中的作用是什么？

②加入Na₂CO₃溶液的目的是什么？

③以上方案还需完善，请说明原因并加以补充。

（4）LiOH和NaOH的化学性质相似。“神舟”飞船内，可用盛有LiOH的过滤网吸收航天员呼出的气体，以降低CO₂含量。请计算：用LiOH完全吸收176 g CO₂生成Li₂CO₃和H₂O，理论上至少需要LiOH的质量是多少？

若长度为n的线性表采用顺序存储结构，在其第i个位置插入一个新元素的算法的时间复杂度为( )(1＜=i＜=n+1)。

A．O(0)

B．O(1)

C．O(n)

D．O(n²)

下列生物中属于雌雄同体，异体受精的是（）。

A、蛔虫

B、猪肉绦虫

B、蚯蚓

D、蝗虫

在下列哪些情况下操作人员应按紧急停止开关，保护现场后立即通知当线工程师或技术员处理：（）

A.回流炉死机

B.回流炉突然卡板

C.回流炉链条脱落

D.机器运行正常