问题 实验题

小明根据实验数据绘制了电阻R2随电阻R1变化的图像,如图所示。请你根据该图像和已有知识判断:当电阻R1=52Ω时,电阻R2=_______Ω。(1分)

答案

18

题目分析:此图有两种做法,第一种是将斜线延长,再用尺子量出对应于R1=52Ω的点R2=18.第二种方法是设R1 R2为两未知数,代入特殊点计算斜率得到二元一次方程并求解R2。

点评:此题学生不需要利用物理中的公式来计算,那样会显麻烦,推荐用第一种方法,作图准确的话准确率是100%的。

选择题
阅读理解

In my opinion, there is only one legitimate (合法的) handgun sport and that is aim practice. It is practiced at objects which are properly monitored and usually quite safe. Only certain handguns are true “sporting weapons”, seen as such by the sport’s lovers.

On the other hand, shooting at tin cans and other small objects in one’s backyard is not and should not be considered a serious sport. When uncontrolled, it can be a very dangerous practice.

Some opponents (反对者) of handgun control have stated that we are out to stop all hunting and that controlling the handgun would severely affect hunting. That is simply untrue. Handgun control would in no way limit the freedom of the true hunter. Few if any hunters consider the handgun an effective hunting weapon.

There are a few hunters who do hunt with handguns, but most states place restrictions (限制) on the type of guns that can be used in hunting, the reason is that killing of game should be done in as humane (人道的) a way as possible. Some small handguns are more likely to wound the animal rather than kill it at once. Only long guns, rifles and shotguns are effective arms of hunting.

People must understand that handguns and hunters are separate matters. Because most of the hunters use a rifle or shotgun, there is no reason why their search for game and sport should be affected by handgun control. Mixing the anti-hunting matter with the handgun matter confuses the killing of animals with killing of people.

小题1:In the writer’s opinion, people should use handguns only when           .

A.hunters shoot at animals

B.they aim at a criminal

C.objects are under control

D.objects are only small tin cans in the backyard小题2:According to the writer, hunting is not affected by handgun control because         .

A.hunters can use knives rather than guns to hunt animals

B.state government encourages hunters to use other guns

C.nobody cares what weapons are used to kill animals

D.most hunters use rifles rather than handguns小题3:This passage mainly talks about           .

A.the relation between hunting and handgun control

B.the importance of aim practice

C.how handgun control affects hunting

D.different types of guns used in hunting