问题 实验题

在“探究平面镜成像的特点”实验中,实验装置如图所示。A、B是两个相同的蜡烛,C是玻璃板。

(1)实验中,发现A 蜡烛成两个像,这两个像之间的距离是由_________决定的。

(2)下表是小明实验中记录的部分实验信息。

①由表中的信息可知,小明所用刻度尺的分度值是_________。

②分析表中的信息,可得到的结论是_____________________。

(3)实验中,若把B 蜡烛也点燃,看到的像不清楚,原因是:________________________________。

答案

(1)玻璃板的厚度

(2)①1mm ②平面镜成像时,像距等于物距

(3)像的亮度一定;点燃B蜡烛,像的背景变亮,像与背景的亮度差异变小。

阅读理解

Can you understand the beginning of this essay?

“My smmr hols wr CWOTT. B4, we usd 2go2 NY 2C my bro, his GF & 3 kds FTF.”

The Scottish teacher who received it in class had no idea what the girl who wrote it meant. The essay was written in a form of English used in cell phone text messages. Text messages (also called SMS2) through cell phones became very popular in the late 1990s. At first, mobile phone companies thought that text messaging would be a good way to send messages to customers, but customers quickly began to use the text messaging service to send messages to each other. Teenagers in particular enjoyed using text messaging, and they began to create a new language for messages called texting.

A text message is limited to 160 characters, including letters, spaces, and numbers, so messages must be kept short. In addition, typing on the small keypad of a cell phone is difficult, so it’s common to make words shorter. In texting, a single letter or number can represent a word, like “r” for “are,”“u” for “you,” and “2” for “to.” Several letters can also represent a phrase, like “lol” for “laughing out loud.” Another characteristic of texting is the leaving out of letters in a word, like spelling “please” as “pls.”

Some parents and teachers worry that texting will make children bad spellers and bad writers. The student who wrote the essay at the top of this page said writing that way was more comfortable for her. (The essay said, “My summer holidays were a complete waste of time. Before, we used to go to New York to see my brother, his girlfriend, and their three kids face to face.”)

Not everyone agrees that texting is a bad thing. Some experts say languages always evolve, and this is just another way for English to change. Other people believe texting will disappear soon. New technology for voice messages may soon make text messages a thing of the past.

小题1:What is the writer’s opinion of text messaging?

A.It is fun and easy to do.

B.It is not bad for children.

C.It will make children bad writers.

D.The writer does not give an opinion.小题2:Which characteristic of texting is NOT described in the passage?

A.Using phrases to represent essays

B.Using numbers to represent words

C.Using letters to represent phrases

D.Using letters to represent words小题3:Which of the following was most probably the title of the student’s essay?

A.My Gr8 Tchr

B.CU in LA

C.My GF

D.My Smmr Hols小题4:   Why do some people think that texting is bad?

A.It costs too much.

B.It’s too difficult to type.

C.Children won’t learn to write correctly.

D.It’s not comfortable.小题5:Why aren’t some people worried about the effect of texting?

A.Not many people use texting.

B.Spelling in English is too difficult.

C.Children quickly become bored with texting.

D.Texting will disappear because of new technology.

判断题