水果含有果酸。如图所示在水果中分别插入两片铜和锌金属极板,就组成了一个水果电池。

题型:实验题

问题:

水果含有果酸。如图所示在水果中分别插入两片铜和锌金属极板,就组成了一个水果电池。某科学兴趣小组对影响水果电池电压大小的因素进行了实验研究。

(1)金属板在水果中插入不同的深度,并保持两块极板之间的距离不变,Hj电压表直接测量两块极板之间的电压,结果如下表:

①  方框里画出这个实验的电路图:

②分析实验数据可以得出:水果电池的电压与_________和________有关;

(2)关于影响水果电池电压大小的因素,你还可以研究的问题是________(写山一个),简单写出你的探究过程___________________________________________________________________________________________________________________。

考点:电压、额定电压
题型:实验题

肝肾不足所致之胎动不安,应首选()

A.紫苏

B.桑叶

C.黄芩

D.桑寄生

E.五加皮

题型:实验题

Have you ever had travel problems because your airplane was late? It is a common problem and it is getting worse. Airport delays make people angry and cost the country billions in lost work time.

The Federal Aviation Administration (FAA) is the government agency that oversees air travel. They studied the problem of airline delays.

They found eleven major problems and suggested eleven ways to fix them. Some of the problems are caused because different regions of the country do things differently. The regions don't talk to each other enough. Some of them need new computers.

Also, more planes are flying. A strong economy has more people using airplanes to get around. Airplanes are a form of mass transportation now, like trains and buses were in the past. More planes in the airport cause delays.

The airport in San Francisco is a good example. It is growing fast. Many people go through San Francisco to get to other places around the world. Ron Wilson of the San Francisco International Airport says, “If you've got 18 flights that all want to take off at 8:00 am and you're on the 18th plane in line, you're going to be 40 minutes late.”

Weather is another main reason for delays. Weather causes about 70% of delays. Fog or freezing rain can cause delays.

The first thing the FAA wants to do is take control away from the regions during heavy traffic times and bad weather. A national center would make decisions on things that affect the whole country. The FAA also wants to put more distance between planes in the sky when the weather is bad. This rule could cause even more delays.

The FAA knows that their solutions will not solve the problems with airport delays. But, they hope to make things better. There are just too many planes, too few traffic controllers, and not enough new technology.

小题1:FAA found that some of the delay problems are caused by ________ between two regions.

A.different languages

B.technical misunderstanding

C.misunderstanding of the rules

D.lack of communication小题2:Which of the following is NOT mentioned as a reason for airline delays?

A.A growing number of flights.

B.Bad weather.

C.A growing population.

D.Lack of new technology小题3:From the passage we can infer that ________.

A.FAA is a national center which controls all the flight matters

B.FAA has taken control to solve airport delays

C.in San Francisco, each plane will delay about 40 minutes

D.safety rules during bad weather may cause more delays小题4:Which of the statements best gives the idea of the passage?

A.FAA should make decisions to stop airport delays.

B.Airport delays are on the rise.

C.Travel problems cost billions in lost work time.

D.FAA has taken control of air traffic nationwide.

题型:实验题

在编写JavaApplet程序时,若需要对发生的事件作出响应和处理,一般需要在程序的开头写上( )语句。

A.import javi*;

B.import javaweven*;

C.import javaw*;

D.import javapple*;

题型:实验题

施工合同管理涉及的有关各方是在施工合同的( )中规定的。

A.合同协议书
B.通用条款
C.专用条款
D.补充协议

题型:实验题

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