如图所示，闭合开关S，灯L发光，把滑动变阻器的滑片P向a端移动，_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

如图所示，闭合开关S，灯L发光，把滑动变阻器的滑片P向a端移动，灯L的亮度与电流表示数的变化情况是（　　）

A．灯L变亮，电流表示数变大

B．灯L变暗，电流表示数变小

C．灯L变亮，电流表示数变小

D．灯L变暗，电流表示数不变

答案

当滑片P向a点移动时，滑动变阻器接入电阻减小，则电路中的总电阻减小；

由欧姆定律可知，在电源电压不变时，电路中电流增大，故电流表的示数变大；

电压表并联在灯泡两端，由欧姆定律可得，灯泡两端的电压增大，灯泡变亮．

故选A．

填空题

VBA编程中，要得到[15,75]上的随机整数可以用表达式______。

阅读理解

阅读理解。

	Atomic (原子的) Watch Price: $ 60 (half price on weekends) Entire time and date exactness (精确) . Water resistant (抵抗的)! A good Italian gift for your friend or your family.
	Jigsaw Puzzle Price: $ 5 (80% price if you take two) Build your own toy! Practice making skills for all ages, especially for children. You can order them in Kuge comp any in Beijing.
	Nesting Dolls Price: $ 4 ( $ 20 a set for six) Wonderful souvenirs (纪念品) for visitors. This nesting doll set was made and hand painted in Russia from Linden (菩提树) wood. This cute and colorful version of the traditional Russian Nesting Dolls is sure to bring
	Atomic Thermograph (温度记录器) Price: $ 30 Made in Canada Indoor temperature range: 32°F to 140°F It's helpful to keep it in your home or in your office. It helps to remind you the change of the temperature or how you'll wear when going out. It can speak two languages-in Chinese or in English.

1. You can get ______ objects which are made in foreign countries.

A. 1
B. 2
C. 3
D. 4

2. How much will you pay for two Jigsaw Puzzles?

A. $ 5.
B. $ 8.
C. $ 10.
D. $ 16.

3. You can pay less money for Atomic Watch during your journey on ______.

A. Wednesday
B. Monday
C. Friday
D. Saturday

4. You can take ______ with you on a rainy day during the trip.

A. Atomic Watch
B. Jigsaw Puzzle
C. Nesting Dolls
D. Atomic Thermograph

5. Which of the following is NOT true?

A. Atomic Watch is very convenient when you are traveling in different continents (大洲).
B. Jigsaw Puzzle is not only a toy, but also a training skill for children.
C. We can recycle plastics for Nesting Dolls.
D. Atomic Thermograph is helpful for you when you plan, to be out.